Fertile and physical evaluation of soil cultivated with cover crops: A review

Introduction

The incorporation of CCs into farming systems produces both internal as well as external the expenses and advantages on the farm. The advantages include enhanced insect control, soil quality (SQ) and water quality (WQ), nutrient cycling efficacy, and cash crop (CCy) yield. Increased direct costs, potential income loss from competition with more profitable crops, difficulty in predicting soil N mineralization, delayed soil warming, and production costs are all costs associated with the adoption of CCs. The advantages of the CCs are more apparent in the majority of irrigated systems. For years, it has been a standard practice in agricultural production to hatch CCs (Reeves, 1994) [1] . Initially, CCs were cultivated as green manure crops, as sources of vegetation, and to enrich soil. Subsequently, CCs were incorporated into soils to enhance fertility (Kaspar and Singer 2011) [2] . Improved environmental conditions and SQ can lead to improved crop productivity (CP) in CCNs. CCs have many uses and enhance soil properties. Crop rotations are important in controlling pests, promoting nutrient mineralisation, suppressing weed establishment and increasing SOM. Application of cover crops (CCs) needs to be supported by ongoing research and sound management to take full advantage of these benefits. A global resurgence of CCs, an age-old approach, has been the consequence of the increasing visibility of conservation agriculture practices that support ecosystem services and enhance sustainable agriculture (Romdhane et al., 2019) [3] . The primary objective of the CCs is to enhance and protect SH (Benedict, et al., 2014) [4] . They can be incorporated into the soil as "green manure" or persist on the surface as mulches, whether they are living or dead (Benedict, et al., 2014; Finney, et al., 2017) [4,5] . Cover crops (CCs) are plants that are cultivated in close proximity to protect and enhance soil quality during the intercrop season or in inter-tree intervals in plantations (Fageria et al., 2005) [6] . The cover crops may consist of a variety of vegetation, but the majority are legumes or grasses that are not legumes. CCs are a viable and sustainable agricultural method to enhance SH and crop performance. They are cultivated to preserve SQ by preventing erosion and nutrient leaching or runoff, inhibiting weed growth, facilitating carbon (C) sequestration, reducing soil compaction, and strengthening soil structure, water infiltration (I), and Λ ᵣₚDΛ: , while also promoting soil microbial populations (Scavo et al., 2022; Unger and Vigil, 1998) [7,8] . For CCs to be successful and context-specific, management techniques and CCs selection are essential. Benefits like nutrient transfer for CCy are often associated with CCs' positive effects on soil characteristics, which function as indicators of SQ. As a result, CCs may provide extra indirect advantages to crops, such as stimulating root growth, especially in fruit orchards (Scavo et al., 2022) [7] . Erenstein (2003) [9] Advocated for the use of CCs as mulches to enhance soil and water conservation, emphasizing the need for early site preparation and crop establishment. To ensure the socioeconomic viability of mulching, adoption should occur through a gradual process that includes educating farmers, securing funding, tailoring practices to local conditions, making improvements, and reforming institutions. This approach will ensure farmer involvement, community support, and thorough safeguarding of natural resources. This paper emphasizes the advantages of CCs in improving the assessment of soil fertility and the evaluation of soil physical properties.

CCs and Their Variety

CCs are numerous and diverse in families (Table 1). Leguminous CCs tend to be slow-growing and involve significant establishment costs. At the same time, they contribute nitrogen to the soil, produce highquality residues in modest quantities (0.5-4 Mg ha -1 ), and create favorable conditions for beneficial insects. Brassica plants produce residues rich in glucosinolates (2-6 Mg ha -1 ), which suppress plant-parasitic nematodes and soilborne pathogens. Among CCs options, leguminous CCs stand out as the most reliable for increasing CCy compared to fallow land or other types. When soil pests severely limit CCy, incorporating leguminous CCs is worth considering. Cereal CCs provide the greatest biomass production (BP), making them the best option fo rapidly increasing SOM. Combinations of leguminous and cereal cover crops or brassica and cereal cover crops show promising results in a variety of ecological settings (Snapp et al., 2005) [10] .

In traditional tillage systems, CP increased by only 2%, while in reduced-tillage organic systems, it increased by as much as 24% when soil was overseen with plant cover crops such as hairy vetch, ordinary vetch, and white tarragon (Wittwer et al., 2017) [11] . Improved the soil's characteristics and aggregate soil ecosystem services are indicated by increases in soil microbial populations. The cultivation and integration of CCs have been demonstrated to substantially increase soil micrograms in specific research studies (Vukicevich et al., 2016) [12] . In accordance with a comprehensive research study, the incorporation of a variety of cover crop species, such as triticale,vetch, rye, bean,phacelia , faba radish, and pea, resulted in a substantial increase in the diversity and quantity of microorganisms that inhabit the soil (Schmidt et al., 2018) [13] . Research also showed that soil treated with a mixture of oats and radishes, or oats, radishes, and vetch, The bacterial phospho fatty acid concentrations increased by 6.8%. and enzyme activity by 20% (Chavarría et al., 2016) [14] . The primary categories of regularly cultivated CCs worldwide are leguminous , grass, and non-leguminous broadleaf plants. The decomposition and substantial soil coverage of grass species are highly valued, while broadleaf species are employed for their rapid decay and the ability to enrich the soil with residues, whilst leguminous species are employed for their N-fixing capabilities. Incorporating CCs into traditional agricultural systems may decrease ρb and enhance soil structure and hydraulic characteristics, hence promoting more I and θ. Additions of crop residues from CCs may improve the accumulation of SOC and N, in addition to increasing the accessibility of phosphorus, potassium, iron, magnesium, and calcium in specific soil types under specific climatic conditions (Koudahe et al., 2022) [15] . The leadership of CCs between CCy is a classic agricultural strategy that is currently garnering global attention (Romdhane et al., 2019) [3] . Any plant species that are used for purposes apart from producing grain or fodder are considered CCs; they are often divided into three categories: grasses, non-leguminous broadleaves, and leguminous broadleaves. According to SSSA, CCs are used to protect and improve the soil in between yearly crop cultivation or between grapes in winemakers and trees in forests (Fageria et al. 2005) [6] . Many of the benefits of CCs may be realized only with correct administration. The successful application of CCs requires careful preparation and the choice of suitable kinds, seeding rates, planting seasons, terminate phases, and termination processes (Wortman et al., 2013; Alonso-Ayuso et al., 2014 ) [16,17] . Termination strategies, termination stages, and species selection are the most critical components of management techniques that are essential for optimizing CCs to prevent nutrient immobilization and competitiveness with subsequent organisms, while simultaneously providing numerous benefits CCy (Wayman et al., 2015) [18] . [32]

Strawberry clover

Trifolium fragiferum (Folorunso et al., 1992) [33]

Bromegrass

CCs and soil Physical Evaluation (SPE)

The soil's physical properties, including θ, ρb, and porosity (n), influence its quality. Based on these characteristics, it may determine how efficiently the soil stores water and nutrients. The physical characteristics of the soil influence both the movement of nutrients and water to the rhizosphere and the animals that live in it. When it comes to flow (v) and I, n is the most significant physical characteristic. The soil pore categorization (Soil Science Society of America, 2008) [34] states that macropores and micropores drain when the tension is less than 3 cm and 3 to 300 cm, respectively. Micropores store water that plants may access, but macropores and mesopores allow water to drain naturally.

Macropores have a high level of pore consistency. The mesopore system, on the other hand, contains fewer continuous pores and more twists and bends (Luxmoore, 1981; Messing and Jarvis, 1993) [35,36] .

Currently, multiple research have proved the effectiveness of CCs in agricultural output, with many of them concentrating on soil physical, chemical, or biological factors (Saleem et al., 2020; Adetunji et al., 2020) [37,19,37,19] . In fact, Saleem et al.( 2020) [37] revealed that the increased root growth of CCs may bring soil benefits, such as increased nutrient availability, elevated SOC levels, and improved soil aggregation. Furthermore, CCs have been demonstrated to facilitate nutrient cycling, the soil's features soil insect control, and weed suppression. CCs conserve θ for subsequent crops by reducing water soil evaporation, as per Sharma et al. (2018) [38] . In specific circumstances, this phenomenon has been observed. In the absence of irrigation, CCs frequently limit θ for future crops in water-limited conditions, as demonstrated by Basche et al. (2016) [39] (Nielsen et al., 2015a; Nielsen et al., 2015b) [40,103] . Enhancing soil physical characteristics is crucial for soil conservation. CCs may enhance physical characteristics and SOM, hence mitigating soil erosion and improving SP and environmental quality. The article reviews the advantages of CCs for enhancing soil physical and hydraulic qualities, along with potential soi conservation benefits. The review demonstrates that CCs diminish ρb by around 4%, augment macropore volume by about 33%, and enhance I by up to 629% relative to soil without CCs. These enhancements have been shown to result in a decrease in soil loss by up to 96% (Haruna et al., 2020) [41] . Numerous research have established the impact of CCs on agricultural systems (Mukumbareza et al., 2015; Coombs et al., 2017 ) [43,42] . The benefits may include enhancements in soil properties , improved soil chemical properties, biological features, and other benefits, such as reduced production costs. The soil water table (WT) has been significantly enhanced and θ has been significantly increased in a variety of soils that have been modified with CCs, such as hairy vetch and rye (Qi and Helmers, 2010) [44] . CCs help the following crops to access θ, stop soil evaporation, retain soil water and irrigation water, and reduce the kinetic energy (kE) of the falling rain drops to the soil surface (Sharma et al. 2018) [38] . In addition, CCs diminish wind erosion and the process of precipitation as well as the emission of particulate matter caused by wind and machine operations (Blanco-Canqui et al., 2011) [24] . CCs can be used to control weeds by competing for light, water and nutrients, and/or by producing chemicals that affect other plants (Masilionyte et al., 2017) [45] . CCs also increase the sequestration of carbon, soil stability in aggregates, and control of insectsall beneficial (O'Reilly et al., 2011) [46] .

CCs and soil fertility Evaluation (SFE)

CCs can alter soil properties by enhancing the availability of soil nutrients for current crops by increasing soil Organic Matter (SOM) combined with a high C:N ratio (Hubbard et al., 2013) [47] . CCs increase available N via biological N fixation and also are able to retain excess soil N for subsequent planting season (O'Reilly et al., 2012) [48] . The benefits of CCs are that they can reduce atmospheric CO₂ and N₂O emissions and increase C and N in soil (Fageria et al. 2005) [6] . When used with conservation tillage, CCs can increase SQ and CP (Schomberg et al., 2009) [49] . CCs can also be able to fix nitrogen in the air, sequester carbon in the soil and limit weed growth (Möller et al., 2008) [50] . In contrast to non-leguminous CCs, it is anticipated that leguminous CCs will incorporate between 60 and 80 kg ha ¹ of N into the soil. Nonleguminous CCs may also absorb surplus soil N, thereby⁻ reducing nitrogen loss (Fisk et al., 2001) [51] . In comparison to the no-CCs (NCC) group, the use of an annual medic or clover CCs in no-till maize led to a 41-81% reduction in winter annual weeds. The incorporation of OM into the soil by CCs may enhance SQ by reducing compaction, increasing I, reducing water and nutrient runoff, and diminishing non-point-source contamination (Wyland et al., 1996) [52] . It was determined that the leaching of nitrate (NO₃ ⁻) was reduced by 65-70% when CCs were substituted for winter waste. Soil loss caused by impact separation is prevented by CCs through the reduction of kE (Haramoto and Gallandt, 2005) [53] .

The solitary CCs are unable to offer all of these benefits. However, the acquisition of a fleet of CCs could be highly advantageous from both an agricultural and environmental standpoint. [54] . SOC is crucial for the enhancement of environmental sustainability and CP. Reports suggest that SOC improves microbial activity and homogenizing the soil within the soil ecosystem (Zhu et al., 2019) [55] , as well as impacts the supply of water (Drenovsky et al., 2004) [56] , accessibility to nutrients (Weintraub et al., 2007) [57] , and CP (Nkongolo and Haruna, 2015) [58] . The accumulation of SOC leads to an increase in C sequestration, which in turn enhances environmental sustainability (West and Marland, 2003) [59] .

Some strategies of soil sustainability and their interaction with CCs

• Incorporation of CCs into Crop Rotation Cycles

An effective approach to mitigate erosion of soil and properly oversee soil and its nutrients for improved production is to integrate CCs into crop rotation cycles. CCs are cultivated for their numerous benefits, including their ability to protect the soil from water and wind erosion (Dabney et al., 2001) [60] .

Covering the soil with both live CCs and their residuals reduces transpiration and aids in maintaining the conservation of θ. CCs may diminish the development of surface seals, thereby enhancing soil water movement and decreasing runoff (Ruan et al., 2001) [61] . Additionally, n can be improved by creating bio-pores and increasing earthworm activity (Lal et al., 1991) [62] . CCs have been shown to enhance soil physical characteristics by diminishing ρb (Blanco-Canqui et al., 2011; Haruna et al., 2018a) [24,62] , improving SOC and aggregate (Steenwerth and Belina, 2008) [26] , increasing macropores (Cercioglu et al., 2018) [65] , developing a θ (Basche et al., 2016) [39] , saturated conductivity indices of water (Ksat) (Yu et al., 2016) [66] , and I (Haruna et al., 2018b) [66] , and limiting soil loss.

• Incorporation of CCs into Tillage Systems

Adding CCs may enhance no-till work by altering the appearance and texture of the soil. Sunn hemp (Crotalaria juncea L.) boosted total I three times more than non-CCs plots and decreased near-surface ρb by 4%. Without N, sunn hemp and late-maturing soybean [Glycine max (L.) Merr.] reduced soil compactibility by 5% (Proctor maximum ρb).

The reduction indicated that soils beneath CCs were less prone to getting compacted. In the 0-7.5 cm depth range, CCs also increase the average weight thickness of sediments by 80%. This research showed that between 0 and 7.5 cm of depth, late-maturing soybeans had 20% more SOC, and sunn hemp had 30% more than plots without CCs (Blanco-Canqui et al., 2011) [24] .

• Incorporation of CCs into soil mulching

Intercropping is the most effective management strategy for integrating CCs into a system of cropping to improve BP. When combined with primary crops, CCs serve as living mulches, allowing farmers to cultivate CCs without compromising acreage for the manufacturing of predominant crops (Afshar et al., 2018; Alonso-Ayuso et al., 2020) [68,69] . Intercropping is the process of producing two or more crop species concurrently within a particular area throughout the growing season (Brooker et al., 2015) [70] . Secondary crops, such as leguminous cover crops, are typically shorter plants that use scattered sunlight to grow alongside the main crop, like organic winter wheat, in relay intercropping systems. Through effective light resource partitioning made possible by this process, the major crop receives direct sunlight while the secondary crops rely on indirect light, increasing resource availability and the agricultural system's overall performance (Amossé et al., 2013) [71] . Adopting the practice of intercropping led to better use of resources more efficiently (Morris and Garrity, 1993) [72] . All studies on intercropping are based on the idea that resource use is best when different types of crops are grown together instead of just one type. Managing differences in how the species uses growing resources or acts in the environment where it is grown leads to that optimization. Therefore, the successful operation of intercropping systems is crucial for the efficiency in farming practices, since the crops compete for the essential resources such as light, water and nutrients, which can affect their growth and CP. Weed control is also difficult as the number of chemicals is limited, and may be affected by crop interactions, which may cause disruption in field operations and reduce CP if not managed properly (Gitari et al. 2020) [73] . Intercropping might be considered unprofitable and/or uneconomical by farmers. Hence, theory and practice have to be combined to create efficient management strategies that maximize resource use efficiency in CCS intercropping system. The literature on how to maximize resource use through intercropping has been directed towards management strategies such as interspecific connections, such as competition and facilitation (Hu et al., 2016) [101] . Balanced crop combination of intercropping certain crops like safflower and bitter vetch in certain combinations as per research has been found to increase BPE and land use efficiency by reducing inter species competition and use of common resources. However, mixtures of mustard and legumes such as peas, lentils or chickpeas can result in significant reductions in individual CP and choosing appropriate intercropping patterns is essential to maximize productivity and sustainability (Banik et al., 2000) [75] . The results indicate that the use of resources in intercropping cereals and legumes is superior to monocropping as the crops have a better interaction with each other. But if they are to be productive, they must be managed in a manner that observes some fundamental natural principles of efficient use of resources. The efficacy of component crops in resource competition is quantified by intercropping indices. Nevertheless, BP data from intercropping CCs are rarely used to analyze these variables because the majority of research focuses on CP. As a result, a wealth of information on intercropping indices for intercrop systems is available, which may be used to evaluate the comparability of CPs (Banik et al., 2000; Gitari et al., 2020; Iqbal et al., 2019) [75,73,76] . This data can be used optimize BP by intercropping CCs using a number of management options.Relay intercropping allows for the deferral of cover crop planting, increasing crop dominance and reducing resource restrictions (Amossé et al., 2013; Brooker et al., 2020; Mhlanga et al., 2016) [71, 77, 78] . Setting up dominant crop growth prior to planting CCs will improve their access to growth resources. On the other side, the main crop has an advantage in terms of timing, which hampers CCs' growth and development (Belfry and Van Eerd, 2016) [79] (Mhlanga et al., 2016) [78] showed that planting CCs between growing corn could slow their growth and not really improve the CP of the intercropping plants. Research demonstrates that intercropping potatoes with legumes, such as climbing beans and similar species (dolichos), can boost land-use efficiency and SP through the application of diverse analytical tools to evaluate agricultural system performance. Evidence suggests that these systems offer a viable strategy for intensifying production, particularly for smallholder farmers, by optimizing resource use and promoting sustainable agriculture (Gitari et al., 2020) [73] . After discussing the aforementioned points, one may be curious about the concepts of soil mulching, cover crops, and intercropping. In brief: 1. Soil mulching: These can be either natural, such as plant residues and rocks, or artificial, like petroleum-based products or agricultural plastic used to cover the soil surface. 2. Plants known as "cover crops" grow to cover the soil's surface, preventing it from exposure and easy erosion. CCs crops do not include any CCy.

Intercropping: This involves planting two types of crops,

either economic or non-economic, in the same field. For instance, you can plant different crops between rows.

• Incorporation of CCs into Soil water content (θ)

Living mulches can have a big effect on the link between soil and water, but the amount depends on the species, the farming system, the temperature, and the type of soil. Most agronomists now concur that understory plants play a crucial role in farming systems, preventing soil loss due to v. By putting CCs between rows of an economic crop, you can make the agroecosystem more diverse. These results show that intercropping potatoes and legumes may be a beneficial way to increase CP, especially for small-scale farmers (Baldé et al., 2011) [80] . Usually, conventional ploughing methods leave open soil between rows of crops. This makes the soil less solid, more likely to be washed away by rain and wind, and it breaks down quickly. When raindrops hit the soil, they can wear away at bare soil. Still, the branches and leaves of CCs can cover the earth and keep most of the rain out, making rain splash less of a problem (Blanco-Canqui et al., 2011) [24] . So, in live mulch systems, leftovers and understory plants can make v more difficult and slow it down, which is very important for stopping soil runoff. Furthermore, rainwater that penetrates living mulch through absorption can help keep water in the soil and speed up the process of I. CCs make the earth less solid, more stable, and better at letting water in through the woody roots, which are made longer by the arbuscular mycorrhizal fungi system (Arruda et al., 2021) [80] , (Blanco-Canqui et al., 2011) [24] . Living mulch soil cover keeps more water in the soil than bare soils, but the effect depends a lot on how much water the species of living mulch use (Liedgens et al., 2004) [82] .

Intercropping has demonstrated its ability to enhance CP from the same land area by making use of water that might otherwise be lost in monoculture systems to less efficient crops. However, soil type significantly influences its θ and the volume of water plant roots can extract across varying θ. In dryland farming, data comparing water use in intercropping systems with the water conserved by living cover crops is scarce. Some researchers suggest that the difference in water use between intercropping and monoculture systems during the growing season may be less than the weighted average (Morris & Garrity, 1993) [71,72] . While intercropping systems generally require more water than monocultures, the actual amount depends heavily on climate and the selected crop species. As these systems can fulfill the water needs of high-yielding monocultures, they present valuable opportunities for agricultural development in water-scarce regions. Nevertheless, the water use of intercropping in dryland areas with rainwater harvesting (RWH) systems remains poorly understood. For instance, in waterlogged conditions, intercropping water consumption (ETc) surpasses the combined water use of individual crops. Due to water competition and complementary use during the growing season, intercropping ultimately consumes less water than the cumulative total of sole crops (Yin et al., 2018) [82] . Scientific findings differ regarding the impact of living mulches on θ. Certain studies indicate that these mulches can compete with plants for water, leading to reduced θ in mulched areas compared to those without mulch (Qu et al., 2019) [83,84] . Live mulches have been demonstrated to increase soil moisture in other investigations (Liedgens et al., 2004; Ni et al., 2016; Thorsted et al., 2006) [82,85,86] . In the range of 0 to 5 centimeters, the soil moisture was increased by the living covering of turf grass, as observed by Ni et al.( 2016) [85] . However, there was no effect on the soil moisture from 5 to 10 cm. In contrast, a separate investigation discovered that transpiration caused water competition at depths of 10-20 cm and 20-40 cm in living mulches (Qu et al., 2019) [84] . Living mulches in wheat systems led to an increase in water evaporation from the soil surface (Thorsted et al., 2006) [86] . In the same vein, the water content of the soil was decreased at depths of 30-90 cm when Italian ryegrass mulch was used in comparison to exposed soil (Liedgens et al., 2004) [82] .

Research shows that maize cultivated as a sole crop retains higher transpirable soil water than systems with living mulches, suggesting improved θ utilization in mulch systems (Baldé et al., 2011) [80] . However, other studies indicate CCs have no effect on θ (Nielsen et al., 2015a; Payero et al., 2021) [40,87] . For example, cotton grown with single or mixed CCs under high rainfall (1400 mm) showed no changes in soil moisture (Payero et al., 2021) [87] . Similarly, corn intercropped with Kura clover exhibited soil moisture levels comparable to pure Kura clover stands (Zemenchik et al., 2000) [88] . Live CCs may reduce soil water via uptake and evaporation (Blanco-Canqui et al., 2011) [24] , though these effects are less noticeable during seasons with normal or above-average rainfall (Wortman et al., 2012) [89] .

Crop

Common effect in studies on: SOM, θ, and ρb Legumes SOM and θ increase moderately, and ρb decreases slightly .

Grasses

SOM and θ increase significantly, and ρb decreases further. Brassicas exhibit a slightly lesser effect compared to grasses, yet they are effective in enhancing θ and SOM.

Conclusions

• CCs haven't been widely accepted by farmers, even though they have positive effects on many agroecosystem services (Mendes et al., 2013) [90] . • Research indicates that inadequate CCs management can negatively impact CCy by competing for water and nutrients, potentially leading to disease spread or inhibiting seed development (Stipešević & Kladivko, 2005) [91] . Some factors that might deter the use of CCs to improve soil and protect wildlife include the direct and indirect costs of seeds, cultivation, and management, as well as the risk of animal grazing during winter (especially in small-scale farming) and potential economic losses (Snapp et al., 2005) [10] . Several studies, however, have shown that the benefits of CCs outweigh their drawbacks (Miguez & Bollero, 2005) [92] . • Soil moisture (θ): As CCs grow, they can help the earth dry out and get warmer in the spring. This may make farming easier but hinder plant growth. When it rains a lot in the winter, CCs growth can help get rid of extra water. Deeprooted CCs such as fodder radish, plantain, and stubble turnips enhance I into the soil by three times. But if it's a dry year, the CCs may take away water from the crops below, making less water available for them. To maximize θ, consider soil type, rain, and CCs.

• Tillage and bulk density (ρb): CCs can improve SQ and notill performance, as shown in sunn hemp plots. They reduced near-surface ρb and I by 4%, while nutrient-free sunn hemp and late-maturing soybean reduced compatibility by 5%. CCs also increased aggregate mean weight diameter by 80% in the 0-7.5-cm layer, while sunn hemp and soybean plots had higher SOC (Blanco-Canqui et al., 2011) [24] . • Soil organic matter (SOM): It can be challenging to tell how CCs change the total amount of OM in the soil, especially in short-term tests and when the CCs aren't very productive. Several studies have found that SOM has stayed the same, while others have found rises ranging from 0.3% to 42% (compared to no CCs). It's important to note that no studies have shown that using CCs lowers the amount of SOM. SOM is more likely to rise in places where crops were killed later, when they had more stems and deeper, thicker roots. Low C: N crops break down faster and don't change the SOM as much over time. When CCs are well-established, they can contribute 1-3 t ha -1 of OM, which is lower than the 4-5 t ha -1 typically provided by most organic manures. However, organic manures, particularly compost, are more effective at retaining carbon (C) in the soil compared to CCs.

Finally, based on the previous three conclusions, the results of this study demonstrate that the different types of CCs have different impacts on important soil attributes such as θ, SOM and ρb as described earlier. To summarize these results, a descriptive graph (Figure 1) and tabulated data (Table 2) is provided for clarity only, and to give an approximate illustration of the differential effects of CC on these soil properties. This graphical and tabular output summarizes the relationships that they observed, and will be a summary of the entire study before presenting recommendations. Moreover, the increase or decrease percentages of these properties can be compared with the results of previous studies, which are mentioned below: [13,26,88] , CCs, especially grasses and legumes, contribute to an increase in SOM of 10-40% compared to non-CCs. [39,41,44] . [24,28,62] , ρb decreases by 4-7% after applying CCs, especially grasses. • Diversity of Benefits: CCs have been found to have positive effects in numerous studies; however, these e c effects subject to significant variation based on the soil type, elevation, and weather conditions d during the CCs' growth phase (Poeplau & Don, 2015) [93] . CCs are typically cultivated in winter in moist -5% e continental and subtropical regions, when the climate is cooler and potentially drier than during the r eprimary crop growing season. Establishing CCs after the primary crop is a difficult task in regions that I n are semi-arid and where water is scarce and droughts are frequent during non-growing seasons (Idowu & Grover, 2014) [94] . For instance, Holman et al.(2012) [95] found that the viability of CCs in semi-arid -10% SOM θ ρb southwestern Kansas, USA, was significantly influenced by the selection of species and the implementation of management strategies that were specifically designed for dry environments. In order to improve sustainability under both conventional and organic management, farmers worldwide are incorporating CCs into a variety of agricultural systems (Clay et al., 2020) [96] . • Economic Benefit: The growing interest from researchers and funders has led to research on the benefits and uptake of CCs. Kladivko et al.(2014) [97] report that in Ohio, Indiana, Illinois, Iowa and Minnesota, 34-81% of fields were in CCs because of increasing awareness of benefits for soil health. The economic and agronomic benefits of CCs can increase soil productivity which in turn increases the likelihood of adoption by farmers (Arbuckle & Roesch-McNally, 2015) [102] . The mechanisms that underlie the benefits of CCs have not been fully understood, and there have been mixed or conflicting findings in many studies (Haruna et al., 2020) [41] . Soil fertility and physical evaluations must be made with the most stable and least changeable properties such as soil pH and soil texture. These properties give an unambiguous idea about the identity of the soil and can be used to make an initial simplified decision. Long-term effects from the CCs on the properties should also be taken into account, because they can also have a significant effect on the pH and soil texture over the long term. Since soil texture is very hard to change and changes may not happen for hundreds or thousands of years, the properties of ρb and structure become very important in determining other physical properties. These characteristics have an important impact on changes in a, θ, and rpD, which in turn impact changes in overall SH and SP. Some Concepts for Future Studies • The possibility of Incorporation of CCs into Soil amendments Applying CCs along with soil amendments is a powerful strategy to enhance SH and CP. Here are some key points on how to effectively integrate CCs with soil amendments: 1. The selection of CCs: The choice of CCs depends upon your soil type, climate and primary crop needs. Legumes are often used, such as clover and vetch, but grasses like rye and oats and brassicas like radish and mustard are also used. 2. Timing: Plant CC in off-season/as intercropping with main crops. This will give a sustained ground cover and maximise benefits.

Incorporation Methods:

Once the CCs have developed, they can be incorporated into the soil by techniques such as mowing, rolling, or tilling. This helps in adding OM and nutrients to the soil. 4. Soil Amendments: Mix CCs and use an organic amendment like compost, manure or biochar. The amendments help to create a more favourable soil structure and provide more nutrients for the soil along with boosting microbial activity.

Monitoring and Management: Regularly monitor SH

indicators such as pH, nutrient levels, and OM. Fine-tune cover crop and amendment plans according to the outcomes. 6. Benefits: CCs and soil amendments may increase soil fertility, soil θ, and decrease erosion and increase CP.

The possibility of compensating for ploughing and its adverse effects by planting CCs, which contributes to improving the properties of the soil that the ploughing works on.

Recommendations for Practice

To effectively integrate CCs into agricultural systems and maximize their benefits for soil fertility and physical properties, the following practical recommendations are proposed: 1. Cover Crop Selection: Select CCs according to regional climate and soil type and main crop requirements. Droughttolerant species such as sorghum-sudangrass, vetch or sunn hemp are suggested in dry and semi-arid areas, because they have the ability of biomass production and root development.

Planting Time:

To minimize land competition, plant CC during the off-season or inter-row during the main crop growth cycle. Planting in dry climates should take place immediately after rain or irrigation to aid germination.

Termination Strategies:

End CC before they become a serious competitor for main crop for nutrients and water. In an organic system, mechanical termination (rolling or mowing) is preferred and in a conventional system, chemical termination can be used.

References

1. Reeves DW. Cover crops and rotations. Crops residue management. Boca Raton: CRC; 1994.
2. Kaspar TC, Singer JW. The use of cover crops to manage soil. Soil management: Building a stable base for agriculture. 2011:321-337.
3. Romdhane S, Spor A, Busset H, Falchetto L, Martin J, Bizouard F, et al. Cover crop management practices rather than composition of cover crop mixtures affect bacterial communities in no-til agroecosystems. Frontiers in microbiology. 2019;10:1618.
4. Benedict C, Cogger CG, Andrews NN. Methods for successful cover crop management in your home garden. 2014.
5. DM, Buyer JS, Kaye JP. Living cover crops have immediate impacts on soil microbia community structure and function. Journal of Soil and Water Conservation. 2017;72(4):361-373.
6. Fageria NK, Baligar VC, Bailey BA. Role of cover crops in improving soil and row crop productivity. Communications in soil science and plant analysis. 2005;36(19-20):27332757.
7. Scavo A, Fontanazza S, Restuccia A, Pesce GR, Abbate C, Mauromicale G. The role of cover crops in improving soil fertility and plant nutritional status in temperate climates. A review. Agronomy for Sustainable Development. 2022;42(5):93.
8. Unger PW, Vigil MF. Cover crop effects on soil water relationships. Journal of soil and water conservation. 1998;53(3):200-207.
9. Erenstein O. Smallholder conservation farming in the tropics and sub-tropics: a guide to the developmen and dissemination of mulching with crop residues and cover crops. Agriculture, Ecosystems & Environment. 2003;100(1):17-37.
10. Snapp SS, Swinton SM, Labarta R, Mutch D, Black JR, Leep R, et al. Evaluating cover crops for benefits, costs and performance within cropping system niches. Agronomy journal. 2005;97(1):322-332.
11. Wittwer RA, Dorn B, Jossi W, van der Heijden MG. Cover crops support ecological intensification of arable cropping systems. Scientific reports. 2017;7(1):41911.
12. Vukicevich E, Lowery T, Bowen P, Úrbez-Torres JR, Hart M. Cover crops to increase soil microbial diversity and mitigate decline in perennial agriculture. A review. Agronomy for Sustainable Development. 2016;36:1-14.
13. Schmidt R, Gravuer K, Bossange AV, Mitchell J, Scow K. Long-term use of cover crops and no-till shift soil microbial community life strategies in agricultural soil. PloS one. 2018;13(2):e0192953.
14. Chavarría DN, Verdenelli RA, Serri DL, Restovich SB, Andriulo AE, Meriles JM, et al. Effect of cover crops on microbial community structure and related enzyme activities and macronutrient availability. European journal of soil biology. 2016;76:74-82.
15. Koudahe K, Allen SC, Djaman K. Critical review of the impact of cover crops on soil properties. International Soil and Water Conservation Research. 2022;10(3):343-354.
16. Wortman SE, Francis CA, Bernards MA, Blankenship EE, Lindquist JL. Mechanical termination of diverse cover crop mixtures for improved weed suppression in organic cropping systems. Weed Science. 2013;61(1):162-170.
17. Alonso-Ayuso M, Gabriel JL, Quemada M. The kill date as a management tool for cove cropping success. PloS one. 2014;9(10):e109587.
18. Wayman S, Cogger C, Benedict C, Burke I, Collins D, Bary A. The influence of cover crop variety, termination timing and termination method on mulch, weed cover and soil nitrate in reduced-tillage organic systems. Renewable Agriculture and Food Systems. 2015;30(5):450-460.
19. Adetunji AT, Ncube B, Mulidzi R, Lewu FB. Management impact and benefit of cover crops on soil quality: A review. Soil and Tillage Research. 2020;204:104717.
20. Haruna SI, Anderson SH, Nkongolo NV, Reinbott T, Zaibon S. Soil thermal properties influenced by perennial biofuel and cover crop management. Soil Science Society of America Journal. 2017;81(5):1147-1156.
21. Haruna SI. Influence of winter wheat on soil thermal properties of a Paleudalf. International Agrophysics. 2019;33(3):389-395.
22. Kuo S, Sainju UM, Jellum EJ. Winter cover crop effects on soil organic carbon and carbohydrate in soil. Soil Science Society of America Journal. 1997;61(1):145-152.
23. Sainju UM, Singh BP, Whitehead WF. Long-term effects of tillage, cover crops, and nitrogen fertilization on organic carbon and nitrogen concentrations in sandy loam soils in Georgia, USA. Soil and Tillage Research. 2002;63(3-4):167179.
24. Blanco-Canqui H, Mikha MM, Presley DR, Claassen MM. Addition of cover crops enhances no till potential for improving soil physical properties. Soil Science Society of America Journal. 2011;75(4):1471-1482.
25. Mazzoncini M, Sapkota TB, Barberi P, Antichi D, Risaliti R. Long-term effect of tillage, nitrogen fertilization and cover crops on soil organic carbon and total nitrogen content. Soil and tillage research. 2011;114(2):165-174.
26. Steenwerth K, Belina KM. Cover crops enhance soil organic matter, carbon dynamics and microbiological function in a vineyard agroecosystem. Applied soil ecology. 2008;40(2):359-369.
27. Jokela WE, Grabber JH, Karlen DL, Balser TC, Palmquist DE. Cover crop and liquid manure effects on soil quality indicators in a corn silage system. Agronomy Journal. 2009;101(4):727-737.
28. Nascente AS, Li Y, Crusciol CAC. Soil aggregation, organic carbon concentration, and soil bulk density as affected by cover crop species in a no-tillage system. Revista Brasileira de Ciência do Solo. 2015;39:871-879.
29. Chen G, Weil RR. Penetration of cover crop roots through compacted soils. Plant and Soil. 2010;331:31-43.
30. Garcia RA, Li Y, Rosolem CA. Soil organic matter and physical attributes affected by crop rotation under no till. Soil Science Society of America Journal. 2013;77(5):1724-1731.
31. Carof M, De Tourdonnet S, Coquet Y, Hallaire V, Roger Estrade J. Hydraulic conductivity and porosity under conventional and no tillage and the effect of three species of cover crop in northern France. Soil Use and Management. 2007;23(3):230-237.
32. Wilson GF, Lal R, Okigbo BN. Effects of cover crops on soil structure and on yield of subsequent arable crops grown under strip tillage on an eroded Alfisol. Soil and Tillage Research. 1982;2(3):233-250.
33. Folorunso OA, Rolston DE, Prichard T, Loui DT. Soil surface strength and infiltration rate as affected by winter cover crops. Soil Technology. 1992;5(3):189-197.
34. Soil Science Society of America. Glossary of soil science terms 2008. ASA-CSSA-SSSA; 2008.
35. Luxmoore RJ. Micro-, meso-, and macroporosity of soil. Soil Sci. Soc. Am. J.;(United States). 1981;45(3).
36. Messing I, Jarvis NJ. Temporal variation in the hydraulic conductivity of a tilled clay soil as measured by tension infiltrometers. Journal of Soil Science. 1993;44(1):11-24.
37. Saleem M, Pervaiz ZH, Contreras J, Lindenberger JH, Hupp BM, Chen D, et al. Cover crop diversity improves multiple soil properties via altering root architectural traits. Rhizosphere. 2020;16:100248.
38. Sharma P, Singh A, Kahlon CS, Brar AS, Grover KK, Dia M, et al. The role of cover crops towards sustainable soil health and agriculture-A review paper. American Journal of Plant Sciences. 2018;9(9):1935-1951.
39. Basche AD, Kaspar TC, Archontoulis SV, Jaynes DB, Sauer TJ, Parkin TB, et al. Soil water improvements with the longterm use of a winter rye cover crop. Agricultural Water Management. 2016;172:40-50.
40. Nielsen DC, Lyon DJ, Hergert GW, Higgins RK, Holman JD. Cover crop biomass production and water use in the Central Great Plains. Agronomy Journal. 2015a;107(6):2047-2058.
41. Haruna SI, Anderson SH, Udawatta RP, Gantzer CJ, Phillips NC, Cui S, et al. Improving soil physical properties through the use of cover crops: A review. Agrosystems, Geosciences & Environment. 2020;3(1):e20105.
42. Coombs C, Lauzon JD, Deen B, Van Eerd LL. Legume cover crop management on nitrogen dynamics and yield in grain corn systems. Field crops research. 2017;201:75-85.
43. Mukumbareza C, Muchaonyerwa P, Chiduza C. Effects of oats and grazing vetch cover crops and fertilisation on microbial biomass and activity after five years of rotation with maize. South African Journal of Plant and Soil. 2015;32(4):189-197.
44. Qi Z, Helmers MJ. Soil water dynamics under winter rye cover crop in central Iowa. Vadose Zone Journal. 2010;9(1):53-60.
45. Masilionyte L, Maiksteniene S, Kriauciuniene Z, Jablonskyte-Rasce D, Zou L, Sarauskis E. Effect of cover crops in smothering weeds and volunteer plants in alternative farming systems. Crop Protection. 2017;91:74-81.
46. O'Reilly KA, Robinson DE, Vyn RJ, Van Eerd LL. Weed populations, sweet corn yield, and economics following fall cover crops. Weed Technology. 2011;25(3):374-384.
47. Hubbard RK, Strickland TC, Phatak S. Effects of cover crop systems on soil physical properties and carbon/nitrogen relationships in the coastal plain of southeastern USA. Soil and Tillage Research. 2013;126:276-283.
48. O'Reilly KA, Lauzon JD, Vyn RJ, Van Eerd LL. Nitrogen cycling, profit margins and sweet corn yield under fall cover crop systems. Canadian Journal of Soil Science. 2012;92(2):353-365.
49. Schomberg HH, Wietholter S, Griffin TS, Reeves DW, Cabrera ML, Fisher DS, et al. Assessing indices for predicting potential nitrogen mineralization in soils under different management systems. Soil Science Society of America Journal. 2009;73(5):1575-1586.
50. Möller K, Stinner W, Leithold G. Growth, composition, biological N 2 fixation and nutrient uptake of a leguminous cover crop mixture and the effect of their removal on field nitrogen balances and nitrate leaching risk. Nutrient Cycling in Agroecosystems. 2008;82:233-249.
51. Fisk JW, Hesterman OB, Shrestha A, Kells JJ, Harwood RR, Squire JM, et al. Weed suppression by annual legume cover crops in no tillage corn. Agronomy journal. 2001;93(2):319325.
52. Wyland LJ, Jackson LE, Chaney WE, Klonsky K, Koike ST, Kimple B. Winter cover crops in a vegetable cropping system: Impacts on nitrate leaching, soil water, crop yield, pests and management costs. Agriculture, Ecosystems & Environment. 1996;59(1-2):1-17.
53. Haramoto ER, Gallandt ER. Brassica cover cropping: I. Effects on weed and crop establishment. Weed Science. 2005;53(5):695-701.
54. Teasdale JR, Brandsaeter LO, Calegari ADEMI R, Neto FS, Upadhyaya MK, Blackshaw RE. Cover crops and weed management. Non-chemical weed management: principles, concepts and technology. 2007:49-64.
55. Zhu X, Hu Y, Wang W, Wu D. Earthworms promote the accumulation of maize root-derived carbon in a black soil of Northeast China, especially in soil from long-term no-till. Geoderma. 2019;340:124-132.
56. Drenovsky RE, Vo D, Graham KJ, Scow KM. Soil water content and organic carbon availability are major determinants of soil microbial community composition. Microbial ecology. 2004;48:424-430.
57. Weintraub MN, Scott-Denton LE, Schmidt SK, Monson RK. The effects of tree rhizodeposition on soil exoenzyme activity, dissolved organic carbon, and nutrient availability in a subalpine forest ecosystem. Oecologia. 2007;154:327-338.
58. Nkongolo NV, Haruna SI. Effect of tillage and cover crop on corn and soybean yields in a silt loam soil. Procedia Environmental Sciences. 2015;29:15-16.
59. West TO, Marland G. Net carbon flux from agriculture: Carbon emissions, carbon sequestration, crop yield, and landuse change. Biogeochemistry. 2003;63(1):73-83.
60. Dabney SM, Delgado JA, Reeves DW. Using winter cover crops to improve soil and water quality. Communications in Soil Science and Plant Analysis. 2001;32(7-8):1221-1250.
61. Ruan H, Ahuja LR, Green TR, Benjamin JG. Residue cover and surface sealing effects on -infiltration: Numerical simulations for field applications. Soil Science Society of America Journal. 2001;65(3):853-861.
62. Lal R, Regnier E, Eckert DJ, Edwards WM, Hammond R. Expectations of cover crops for sustainable agriculture. cover crops for clen water. Hargrove WL Soil and water conservation society publication, Ankey, USA. 1991:1-11.
63. Cercioglu M, Anderson SH, Udawatta RP, Haruna SI. Effects of cover crop and biofuel crop management on computed tomography-measured pore parameters. Geoderma. 2018;319:80-88.
64. Yu Y, Loiskandl W, Kaul HP, Himmelbauer M, Wei W, Chen L, et al. Estimation of runoff mitigation by morphologically different cover crop root systems. Journal of Hydrology. 2016;538:667-676.
65. Zhu JC, Gantzer CJ, Anderson SH, Alberts EE, Beuselinck PR. Runoff, soil, and dissolved nutrient losses from no till soybean with winter cover crops.-Soil Science Society of America Journal. 1989;53(4):1210-1214.
66. Afshar RK, Chen C, Eckhoff J, Flynn C. Impact of a living mulch cover crop on sugarbee establishment, root yield and sucrose purity. Field Crops Research. 2018;223:150-154.
67. Alonso-Ayuso M, Gabriel JL, Pancorbo JL, Quemada M. Interseeding cover crops into maize: Characterization of species performance under Mediterranean conditions. Field Crops Research. 2020;249:107762.
68. Brooker RW, Bennett AE, Cong WF, Daniell TJ, George TS, Hallett PD, et al. Improving intercropping: a synthesis of research in agronomy, plant physiology and ecology. New Phytologist. 2015;206(1):107-117.
69. Amossé C, Jeuffroy MH, David C. Relay intercropping of legume cover crops in organic winter wheat: Effects on performance and resource availability. Field Crops Research. 2013;145:78-87.
70. Morris RA, Garrity DP. Resource capture and utilization in intercropping: water. Field Crops Research. 1993;34(34):303-317.
71. Gitari HI, Nyawade SO, Kamau S, Karanja NN, Gachene CK, Raza MA, et al. Revisiting intercropping indices with respect to potato-legume intercropping systems. Field Crops Research. 2020;258:107957.
72. Jalilian J, Najafabadi A, Zardashti MR. Intercropping patterns and different farming systems affect the yield and yield components of safflower and bitter vetch. Journal of Plant Interactions. 2017;12(1):92-99.
73. Banik P, Sasmal T, Ghosal PK, Bagchi DK. Evaluation of mustard (Brassica compestris Var. Toria) and legume intercropping under 1: 1 and 2: 1 row replacement series systems. Journal of Agronomy and Crop Science. 2000;185(1):9-14.
74. Iqbal MA, Hamid A, Hussain I, Siddiqui MH, Ahmad T, Khaliq A, et al. Competitive indices in cereal and legume mixtures in a South Asian environment. Agronomy Journal. 2019;111(1):242-249.
75. Brooker AP, Renner KA, Basso B. Interseeding cover crops in corn: Establishment, biomass, and competitiveness in on farm trials. Agronomy Journal. 2020;112(5):3733-3743.
76. Mhlanga B, Cheesman S, Maasdorp B, Mupangwa W, Munyoro C, Sithole C, et al. Effects of relay cover crop planting date on their biomass and maize productivity in a sub-humid region of Zimbabwe under conservation agriculture. NJAS-Wageningen Journal of Life Sciences. 2016;78:93-101.
77. Belfry KD, Van Eerd LL. Establishment and impact of cover crops intersown into corn. Crop Science. 2016;56(3):12451256.
78. Baldé AB, Scopel E, Affholder F, Corbeels M, Da Silva FAM, Xavier JHV, et al. Agronomic performance of notillage relay intercropping with maize under smallholder conditions in Central Brazil. Field Crops Research. 2011;124(2):240-251.
79. Arruda B, Herrera WFB, Rojas-García JC, Turner C, Pavinato PS. Cover crop species and mycorrhizal colonization on soil phosphorus dynamics. Rhizosphere. 2021;19:100396.
80. Liedgens M, Frossard E, Richner W. Interactions of maize and Italian ryegrass in a living mulch system:(2) Nitrogen and water dynamics. Plant and Soil. 2004;259:243-258.
81. Yin W, Yu A, Guo Y, Wang Y, Zhao C, Fan Z, et al. Straw retention and plastic mulching enhance water use via synergistic regulation of water competition and compensation in wheat-maize intercropping systems. Field Crops Research. 2018;229:78-94.
82. Qu B, Liu Y, Sun X, Li S, Wang X, Xiong K, et al. Effect of various mulches on soil physico-Chemical properties and tree growth (Sophora japonica) in urban tree pits. PloS one. 2019;14(2):e0210777.
83. Ni X, Song W, Zhang H, Yang X, Wang L. Effects of mulching on soil properties and growth of tea olive (Osmanthus fragrans). Plos one. 2016;11(8):e0158228.
84. Thorsted MD, Olesen JE, Weiner J. Width of clover strips and wheat rows influence grain yield in winter wheat/white clover intercropping. Field Crops Research. 2006;95(23):280-290.
85. Payero JO, Marshall MW, Davis RH, Bible J, Nemire N. Effect of Rye and mix cover crops on soil water and cotton yield in a humid environment. Open Journal of Soil Science. 2021;11(5):271-284.
86. Zemenchik RA, Albrecht KA, Boerboom CM, Lauer JG. Corn production with kura clover as a living mulch. Agronomy Journal. 2000;92(4):698-705.
87. Wortman SE, Francis CA, Bernards ML, Drijber RA, Lindquist JL. Optimizing cover crop benefits with diverse mixtures and an alternative termination method. Agronomy journal. 2012;104(5):1425-1435.
88. Mendes R, Garbeva P, Raaijmakers JM. The rhizosphere microbiome: significance of plant beneficial, plant pathogenic, and human pathogenic microorganisms. FEMS microbiology reviews. 2013;37(5):634-663.
89. Stipešević B, Kladivko EJ. Effects of winter wheat cover crop desiccation times on soil moisture, temperature and early maize growth. Plant soil environ. 2005;51(6):255-61.
90. Miguez FE, Bollero GA. Review of corn yield response under winter cover cropping systems using meta analytic methods. Crop Science. 2005;45(6):2318-2329.
91. Poeplau C, Don A. Carbon sequestration in agricultural soils via cultivation of cover crops-A meta analysis. Agriculture, Ecosystems & Environment. 2015;200:33-41.
92. Idowu J, Grover K. Principles of cover cropping for arid and semi-arid farming systems. New Mexico State University, College of Agricultural, Consumer and Environmental Sciences. 2014.
93. Holman J, Dumler T, Roberts T, Maxwell S. Cover crop forage biomass yield. Field Day 2012. Rep. of Progress 1070. K-State Res. and Ext. Kansas State Univ. Agric. Exp. Stn. and Coop. Ext. Serv. Southwest Res.-Ext. Ctr. 2012:1217.http://www
94. Clay L, Perkins K, Motallebi M, Plastina A, Farmaha BS. The perceived benefits, challenges, and environmental effects of cover crop implementation in South Carolina. Agriculture. 2020;10(9):372.
95. Kladivko EJ, Kaspar TC, Jaynes DB, Malone RW, Singer J, Morin XK, et al. Cover crops in the upper midwestern United States: Potential adoption and reduction of nitrate leaching in the Mississippi River Basin. Journal of Soil and Water Conservation. 2014;69(4):279-291.
96. Ashford DL, Reeves DW. Use of a mechanical roller-crimper as an alternative kill method for cover crops. American journal of alternative agriculture. 2003;18(1):37-45.
97. Midwest Cover Crops Council. Midwest cover crops field guide (2nd ed.). Purdue University; 2014.
98. Yang Z, Singh BR, Sitaula BK. Fractions of organic carbon in soils under different crop rotations, cover crops and fertilization practices. Nutrient Cycling in Agroecosystems. 2004;70:161-166.
99. Hu F, Gan Y, Chai Q, Feng F, Zhao C, Yu A, et al. Boosting system productivity through the improved coordination of interspecific competition in maize/pea strip intercropping. Field Crops Research. 2016;198:50-60.
100. Arbuckle JG, Roesch-McNally G. Cover crop adoption in Iowa: The role of perceived practice characteristics. Journal of Soil and Water Conservation. 2015;70(6):418-429.
101. Nielsen DC, Lyon DJ, Hergert GW, Higgins RK, Calderón FJ, Vigil MF. Cover crop mixtures do not use water differently than single-species plantings. Agronomy Journal. 2015;107(3):1025-1038. doi:10.2134/agronj14.0506.