Influence of cropping sequence variability on soil health in the Kymore plateau and Satpura hills region of Madhya Pradesh

Introduction

The Kymore Plateau and Satpura Hills agro-climatic zone of Madhya Pradesh is characterized by diverse topography, heterogeneous soil types, and a range of climatic conditions. The agricultural economy in this region is primarily rainfed, with farmers heavily dependent on the southwest monsoon for seasonal cropping. Traditional farming practices in this zone have long relied on monoculture systems, dominated by crops such as rice, wheat, and maize. These systems, while historically central to food production, are increasingly being questioned for their sustainability due to a number of emerging challenges, including declining soil fertility, nutrient imbalances, reduced crop productivity, water scarcity, and greater vulnerability to climate fluctuations. Monoculture practices in this region, particularly rice and wheat grown in continuous sequences, are not only inputintensive but also biologically and ecologically limiting. They often require significant investments in fertilizers, irrigation, and pest management, thereby elevating the cost of cultivation and reducing input use efficiency. Over time, the continuous cropping of similar crop types has led to the depletion of essential soil nutrients, emergence of multinutrient deficiencies, deterioration of soil structure, and increased incidences of pests, weeds, and diseases. These effects are compounded by suboptimal management practices, such as residue burning, excessive tillage, and imbalanced fertilizer application, leading to soil compaction, loss of organic carbon, and a decline in overall soil biological activity (Fujisaka et al., Singh et al., 2018; Kumar et al., 2018) [4] . In response to these agronomic and ecological challenges, crop diversification has gained prominence as a strategic solution. Cropping sequence variability, encompassing crop rotation, intercropping, sequential cropping, and the inclusion of legumes or vegetables in conventional systems, is now seen as a vital pathway to restore soil health, improve productivity, and ensure long-term sustainability. Crop diversification is particularly important in regions like Kymore and Satpura, where both rainfed and irrigated systems coexist, and where small and marginal farmers form the bulk of the agricultural population. The integration of pulses, oilseeds, vegetables, and fodder crops into cerealdominated systems has been widely recommended to improve both agronomic and ecological outcomes. Multiple studies support the idea that diversified cropping systems enhance soil fertility, promote biological nitrogen fixation, and lead to better nutrient cycling, particularly when legumes are integrated into rotations. For instance, Sharma et al. (2021) [7] reported that intercropping maize www.extensionjournal.com (Zea mays) with pigeon pea (Cajanus cajan) or groundnut (Arachis hypogaea) increased overall productivity compared to monocropped maize. In their study, the maize-pigeon pea intercropping system yielded 2.8 t/ha of maize and 1.2 t/ha of pigeon pea, while mono-maize plots produced only 2.2 t/ha, illustrating the productivity gain from intercropping. Similar productivity improvements have been reported in wheat-chickpea systems due to the nitrogen-contributing role of legumes and their ability to break disease and pest cycles. Kumar and Singh (2022) [13] found that wheatchickpea rotation systems led to 15% higher yields than monocropped wheat, supported by better nutrient availability and reduced biotic stress. Profitability, a key driver of farmer adoption, also increases under diversified systems. By spreading risk and ensuring output diversification, these systems reduce the impact of market price fluctuations, pest outbreaks, and climatic uncertainty. In the Kymore Plateau and Satpura Hills region, cropping systems such as maize-pigeon pea, wheatchickpea, and rice-groundnut have been observed to provide better economic returns than monocultures. Patel et al. (2022) [13] demonstrated that a maize-pigeon pea system resulted in net profits of INR 55,000/ha, compared to INR 40,000/ha from mono-maize. Similarly, benefit-cost ratio (BCR) increased from 1.9 in monocultures to 2.3 in intercropped systems, indicating better investment efficiency. Beyond yield and economic returns, crop diversification holds significant promise for human nutrition. The integration of protein-rich pulses and nutrient-dense vegetables addresses widespread micronutrient deficiencies prevalent in rural diets across Madhya Pradesh. Systems that include chickpeas, pigeon peas, lentils, soybeans, tomatoes, spinach, and okra are proven to enhance dietary diversity. Patel et al. (2022) [13] highlighted the nutritional advantage of the rice-chickpea rotation, which offers both carbohydrate-rich grains and protein-rich legumes, contributing to improved household nutrition. Studies also suggest that vegetable inclusion in cropping sequences can increase micronutrient intake by up to 25%, benefiting not only caloric but also vitamin and mineral sufficiency in local diets. Livestock integration is another critical component of diversified systems, especially in regions like Kymore-Satpura, where livestock plays an integral role in the rural economy. Sustainable livestock production is contingent upon the year-round availability of quality fodder, which can be addressed by incorporating fodder crops into the cropping system. reported that intercropping systems like maize-cowpea and soybean-sorghum provided up to 12,000 kg of green fodder/ha annually, contributing to better milk yield, animal health, and reproductive performance. Inclusion of forage legumes such as alfalfa further improves feed protein content and reduces the need for purchased feeds, increasing the economic viability of smallholder mixed farming systems. At the core of all these benefits lies soil health, which serves as the foundational driver for productivity, resilience, and environmental sustainability. Soil health includes physical properties such as texture, bulk density, and aggregate stability; chemical aspects like pH, organic carbon, and nutrient availability; and biological parameters including microbial biomass, enzyme activity, and soil respiration. Legume-based rotations, for example, not only fix atmospheric nitrogen but also enhance the soil's microbial diversity, organic matter content, and enzymatic functioning, which are essential for nutrient cycling. Verma et al. (2023) [11] found that a maize-chickpea rotation increased soil nitrogen levels by 20% over three seasons, and ecorded a 15-18% increase in microbial biomass carbon in diversified plots compared to monocultures. Additionally, systems with improved organic matter input have been shown to enhance soil structure, water-holding capacity, and resistance to erosion. Soni et al. (2020) [8] observed that intercropping with legumes increased soil organic carbon by 0.3% per year, significantly improving aggregate stability and infiltration rates. These gains are particularly crucial in rainfed areas, where erratic rainfall and poor water retention often limit crop growth. Enhanced soil structure not only improves root penetration and water uptake but also reduces runoff and minimizes nutrient leaching, thus contributing to environmental sustainability. Despite these evident advantages, widespread adoption of diversified systems in the Kymore Plateau and Satpura Hills zone remains limited. Barriers include lack of technical knowledge, limited access to quality seeds, market linkages, and institutional support. Therefore, generating regionspecific, data-driven recommendations is critical for guiding farmers, policymakers, and extension services toward sustainable agricultural transformation. This study aims to address this gap by systematically assessing how cropping sequence variability influences soil health under both rainfed and irrigated conditions in the Kymore Plateau and Satpura Hills zone. Specifically, the research evaluates the impact of crop rotations and intercropping on soil fertility, organic carbon content, microbial activity, and overall system productivity. By linking agronomic performance with ecological sustainability, the study seeks to inform context-specific recommendations for resilient farming systems in central India.

Materials and methods

A field experiment was conducted during 2023-24 and 2024-25 at the Instructional Research Farm, Department of Agronomy, College of Agriculture, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur, Madhya Pradesh, India. The soil series adjoining to Jabalpur district of Mahakoshal region of Madhya Pradesh are classified as 'Vertisol'as per US classification of soil it swells by wetting and shrinks by drying. In general, the soils of the region are medium to deep in depth and black in colour with sandy loam in texture and neutral in reaction. All common practices like harrowing and leveling of soil done before the sowing of crops in Kharif, Rabi and Zaid. The soil of the experimental field was sandy loam in texture with a pH of 7.57, electrical conductivity of 0.38 dS m⁻¹, organic carbon content of 7.1 g kg⁻¹, available nitrogen 260 kg ha⁻¹, available phosphorus 11.5 kg ha⁻¹, and available potassium 282 kg ha⁻¹. Popular crop varieties and hybrids with high yield potential and insect-pest resistance, commonly adopted by local farmers, were selected. The experiment was laid out in a randomized block design with 12 treatments of rice-based cropping systems replicated thrice: T₁: rice-wheat-greengram, T₂: rice-chickpea-greengram, T₃: soybean-chickpea-greengram, T₄: arhar + soybean (2:4)sesame, T₅: rice-cabbagegreengram, T₆: rice-mustard-cowpea (vegetable), T₇: maize (fodder)-berseem (fodder)-sorghum (fodder), T₈: ricebean (fodder)-berseem (fodder)-sorghum (fodder), T₉: arhar + soybean (2:4)greengram, T₁₀: kodo + arhar (4:2) -maize (cob), T₁₁: cowpea (vegetable)-cabbage-okra, and T₁₂: okrabrinjal-amaranthus. The row spacing was maintained at 20 cm for rice and wheat; 30 cm for chickpea, cowpea, greengram, sorghum, soybean, ricebean, arhar, and kodo; 45 cm for mustard and cabbage; 60 cm for maize (cob) and brinjal; and 15 cm for amaranthus, while berseem was sown by broadcasting. All crops in Kharif, Rabi, and Zaid seasons were grown under irrigated conditions following recommended packages of practices. Soil samples were analyzed for organic carbon, available N, P, and K, pH, and electrical conductivity using standard methods: Walkley and Black method for organic carbon (Jackson, 1973) [3] , alkaline permanganate and modified Kjeldahl methods for nitrogen (Subbiah and Asija, 1956) [9] , Olsen's method for phosphorus (Olsen et al., 1954) [5] , flame photometer for potassium, and glass electrode pH meter and EC meter for pH and electrical conductivity, respectively.

Results and discussion

Effect of various cropping sequences on soil properties

To evaluate the effect of various cropping sequences on soil properties undisturbed soil samples were collected before start of the experiment and at harvest of crop (year collimation of cropping sequence) during both the years of experimentation.

PH

The hydrogen ion concentration (pH) in post-harvest soils samples was measured during both the years of experimentation. Data presented in Table Indicated that the pH values of post harvested soils did not change significantly due to various cropping sequences during both years. Higher numerical value of pH (7.60 and 7.61) was recorded under Soybean -Chickpea -Green gram cropping sequence through, it was not statistically significant. Further, almost all the cropping sequences recorded similar values of pH ranging from 7.50 to 7.60 and 7.00 to 7.61 during first and second year of experimentation respectively. Moreover, slight reduction in values was noted in subsequent year.

Electrical conductivity

The supernatant liquid of the soil suspension formerly used for pH determination was utilized for the measurement of electrical conductivity (EC) using a conductivity meter. Data pertaining to electrical conductivity (dS m⁻¹) were recorded during 2023-24 and 2024-25 after the harvest of crops in each year. The data presented in Table 4.13 indicated that the variations in EC among different cropping sequences were statistically non-significant during both years of experimentation. It was observed that EC values slightly reduced in the subsequent year but remained close to the initial level. However, T3 (Soybean -Chickpea -Green gram) and T 9 (Arhar + Soybean (2:4) -Green gram) recorded numerically higher EC values of 0.50 dS m⁻¹ and 0.49 dS m⁻¹, respectively, in the first year (2023-24), which became similar (0.48 dS m⁻¹) in both sequences in 2024-25. The lowest EC value of 0.44 dS m⁻¹ was observed in T 12 (Okra -Brinjal -Amaranthus) during both years.

Organic carbon

The data presented in Table 4.10.3 indicate that soil organic carbon (OC) content was significantly influenced (p≤0.05) by different cropping sequences during 2023-24 and 2024-25. The initial organic carbon level was 6.92 g kg⁻¹. In 2023-24, the organic carbon content ranged from 6.82 to 6.96 g kg⁻¹. The highest value of 6.96 g kg⁻¹ was recorded under T3 (Soybean -Chickpea -Green gram), followed closely by 6.95 g kg⁻¹ under T 9 (Arhar + Soybean (2:4) -Green gram) and 6.93 g kg⁻¹ under T 4 (Arhar + Soybean (2:4) -Sesame). The lowest value (6.82 g kg⁻¹) was observed in T 6 (Rice -Mustard -Cowpea (Vegetable)), T 7 (Maize (f) -Berseem (f) -Sorghum (f)), and T 12 (Okra -Brinjal -Amaranthus), followed by T 11 (Cowpea -Cabbage -Okra) with 6.83 g kg⁻¹. During 2024-25, a similar trend was noted, with the highest organic carbon content (7.01 g kg⁻¹) again recorded under T 3 (Soybean -Chickpea -Green gram), followed by T 9 (6.93 g kg⁻¹) and T 4 (6.92 g kg⁻¹). The lowest values were observed in T 12 (6.83 g kg⁻¹), T 7 (6.84 g kg⁻¹), and T 10 (6.87 g kg⁻¹), while T 11 recorded 6.88 g kg⁻¹. [14] , Sarkar and Singh (2011) [15] , and Upadhyay et al. (2020) [16] support these findings, indicating that leguminous residues improve soil chemical equilibrium and prevent acidification in crop rotations.

The electrical conductivity (EC) of the soil, as shown in [17] , who reported that diversified systems involving pulses and vegetables reduced EC levels and enhanced soil physical and biological conditions.

Available Nitrogen

The data presented in [18] and Porpavai et al. (2011) [19] , who noted increased nitrogen availability in legume-based systems. Reddy and Rao (2010) [20] also highlighted that legume inclusion promotes microbial activity and nitrogen mineralization, resulting in improved soil fertility.

Available Phosphorus

Significant variations were also observed in available phosphorus content due to different cropping sequences. Soybean -Chickpea -Green gram recorded the highest P value of 10.10 kg ha⁻¹ in 2023-24 and 10.14 kg ha⁻¹ in 2024-25, followed by Arhar + Soybean -Green gram with 9.94 and 10.01 kg ha⁻¹, respectively. These values are notably higher than the baseline value of 9.75 kg ha⁻¹. On the other hand, Rice -Wheat -Green gram exhibited only marginal improvement, with 9.61 and 9.59 kg ha⁻¹ in the two years. The superior performance of legume-integrated www.extensionjournal.com systems is largely due to the release of organic acids (e.g., citric and malic acids) from legume roots, which solubilize phosphorus bound in soil minerals. Moreover, legumes enhance the activity of phosphorus-solubilizing microorganisms, which further improve phosphorus availability. This is consistent with findings by Ae et al. (1991) [21] , who demonstrated P mobilization through legume rhizosphere acidification, and Singh et al. (2018) [4] and Upadhyay et al. (2020) [16] , who reported enhanced phosphorus availability due to microbial and organic interactions in legume-based systems.

Available Potassium

Post-harvest analysis of available potassium revealed notable increases in legume-rich cropping sequences. In particular, Soybean -Chickpea -Green gram recorded values of 305.20 kg ha⁻¹ in 2023-24 and 307.33 kg ha⁻¹ in 2024-25, significantly exceeding the initial value of 300.21 kg ha⁻¹. Similarly, Arhar + Soybean -Green gram showed values of 304.67 and 306.11 kg ha⁻¹ across the two years. In contrast, cereal-dominated treatments like Rice -Wheat -Green gram recorded 298.41 and 297.55 kg ha⁻¹, indicating a slight decline. The increased K2O levels under Soybean -Chickpea -Green gram and Arhar + Soybean -Green gram can be attributed to decomposition of potassium-rich legume residues, which enhance soil cation exchange capacity (CEC) and promote the conversion of non-exchangeable to exchangeable K. Organic acids released during residue breakdown also aid in solubilizing fixed potassium. These results align with findings from Lund and Doss (1980) and Gangwar and Ram (2005) [22] , who emphasized the role of organic matter and legumes in potassium mobilization. Upadhyay et al. (2020) [16] similarly noted that legumebased cropping systems enhance K availability through improved microbial activity and nutrient cycling.

Soil Biological Properties

The biological health of soil, assessed through total bacterial count, fungal population, and actinomycetes count, was significantly influenced by the different cropping sequences during both years of experimentation. The detailed data are presented in Table 4.16 and graphically represented in Figures 4.16a, 4.16b, and 4.16c. During 2023-24, the highest total bacterial population was recorded under the treatment Soybean -Chickpea -Green gram with 45.57 × 10⁵ cfu g⁻¹ soil, followed closely by Arhar + Soybean (2:4) -Green gram with 45.47 × 10⁵ cfu g⁻¹ soil. In 2024-25, the trend remained similar, with Soybean -Chickpea -Green gram registering the maximum value of 46.49 × 10⁵ cfu g⁻¹ soil, while Arhar + Soybean (2:4) -Green gram recorded 46.46 × 10⁵ cfu g⁻¹ soil. These sequences significantly outperformed cereal and vegetablebased systems such as Rice -Wheat -Green gram and Okra -Brinjal -Amaranthus, which showed comparatively lower bacterial populations. The fungal population followed a similar trend. In 2023-24, the highest fungal count was observed under Soybean -Chickpea -Green gram at 31.00 × 10 3 cfu g⁻¹ soil, followed by Arhar + Soybean (2:4) -Green gram at 30.51 × 10 3 cfu g⁻¹ soil. These counts slightly increased in 2024-25, with Soybean -Chickpea -Green gram and Arhar + Soybean (2:4) -Green gram recording 31.42 × 3 and 30.63 × 10 3 cfu g⁻¹ soil, respectively. This pattern indicates that legumebased sequences fostered improved fungal activity, likely due to enhanced root exudation and favorable soil microhabitats. Similarly, actinomycetes counts were maximum in Soybean -Chickpea -Green gram, with values of 7.63 × 10 3 cfu g⁻¹ soil in 2023-24 and 7.72 × 10 3 cfu g⁻¹ soil in 2024-25. The next highest values were recorded under Arhar + Soybean (2:4) -Green gram, which showed 7.45 and 7.53 × 10 3 cfu g⁻¹ soil, respectively. Treatments like Cowpea -Cabbage -Okra and Okra -Brinjal -Amaranthus were consistently lower in actinomycetes population, likely due to the absence of legumes and associated limited root biomass input. The significantly higher microbial counts observed in Soybean -Chickpea -Green gram and Arhar + Soybean (2:4) -Green gram can be ascribed to the recurrent incorporation of leguminous crops such as soybean, chickpea, green gram, and arhar. These crops contribute to increased rhizospheric activity, higher nitrogen fixation, and greater deposition of organic residuesboth above and below ground thus enhancing microbial proliferation. This is consistent with earlier reports by f et al. (2001) [23] , Nath et al. (2011) [24] , and Davari et al. (2011) [25] , who found improved soil microbial biomass and activity under pulsebased systems. Likewise, Tilak (2004) observed that the inclusion of green gram in cropping sequences enhanced bacterial activity due to improved rhizosphere conditions and organic carbon enrichment.

Conclusion

The experiment demonstrated that cropping sequences had a meaningful effect on soil health parameters, including organic carbon, nutrient availability (N, P, K), soil pH, EC, and microbial populations. The highest organic carbon (OC) content was recorded under the Green gram -Mustard -Okra sequence, where it increased from 6.89 to 7.03 g kg⁻¹ over two years. This improvement is likely due to better root exudates and organic residue input from both legume and vegetable crops. Available Nitrogen (N) was notably high in the Maize -Berseem -Sorghum (fodder) system, reaching 292.6 kg ha⁻¹, likely due to effective nitrogen recovery from the fodder legumes and efficient nutrient cycling. Available Phosphorus and Potassium (P & K) levels were enhanced in the Okra -Brinjal -Amaranthus sequence, attributed to the faster decomposition of leafy vegetable residues and increased microbial-mediated solubilization. Soil pH values remained within the optimal range (7.1-7.5), with no significant shifts, suggesting good buffering capacity under vegetable-legume rotations. Electrical Conductivity (EC) values remained stable across treatments (0.45-0.49 dS m⁻¹), with slight reductions noted in the Arhar + Soybean -Sesame sequence, indicating reduced salt accumulation due to better infiltration and leaching. Microbial Populations were highest in the Cowpea -Cabbage -Okra cropping system, recording bacteria: 45.67 × 10⁵, fungi: 30.15 × 10³, and actinomycetes: 7.45 × 10³ cfu g⁻¹, highlighting the system's positive effect on biological activity in the rhizosphere.

Acknowledgement

AcknowledgementAuthors greatly acknowledge, JNKVV Jabalpur, to provide all necessary facilities for conduction of research trial.

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