Assessment of soil micronutrients from different locations across various districts of Madhya Pradesh in the Narmada River belt

Introduction

Soil is vital for both animals and humans as it serves as the foundation for life on Earth. It provides essential nutrients and minerals necessary for plant growth (Lehmann et al., 2020) [1] . Plants required micronutrients (trace elements) are needed in smaller quantities. Despite their different required levels, micronutrients are vital to plant metabolism. A deficiency of available nutrients in the soil negatively impacts quality of soil, crop yields, nutritional value of agricultural products and consequently, the health of humans. However, soil fertility depletion is the fundamental bio-physical cause for declining per capita food production (Lelago and Buraka, 2019) [2] . Recent report of AICRP on Micro and Secondary Nutrients and Pollutant Elements (AICRP-MSPE) based on 2,40,000 soil samples were collected with the help of GPS from 640 districts of country revealed widespread occurrence of sulphur and micronutrients deficiencies in soils. On an average, 40.8, 36.5, 12.8, 4.2, 7.1 and 23.2% soils have been identified to be deficient in S, Zn, Fe, Cu, Mn B, respectively (Shukla and Behera, 2019) [3] . Deficiency of cationic micronutrients likes Zn, Fe, Mn and Cu have been reported in different soils worldwide (Alloway, 2008) [4] and in Indian soils over the years (Singh et al., 2009) [5] . In India, on an average, 36% of soils have been found deficient in Zn, 13% in Fe, 5% in Cu, 7% in Mn, 23% in B and 13% in Mo. Micronutrients deficiencies in soils, often called "Hidden Hunger" in plants, reduce crop productivity and lead to poor soil health. This creates a cycle of low nutrient availability, poor plant growth and declining soil fertility (Shukla et al., 2016) [6] . Many regions in Madhya Pradesh faces soil nutrient deficiencies, especially in Zn, S and Fe which limit crop production and challenge sustainable agriculture. Low nutrient availability is one of the main problems affecting agricultural productivity in Madhya Pradesh (Dwivedi et al, 2009) [7] . The extent and nature of these deficiencies are affected by factors i.e. soil type, management practices, crop genotype and agro-ecological conditions. Intensive cropping systems involve the exhaustive mining of plant nutrients and lead to depletion of soil fertility (Quddus et al., 2022) [8] wherein a balanced and adequate replenishment of nutrients is continuously ignored. With the introduction of high yielding varieties, use of chemical fertilizers, less addition of farmyard manure and use of marginal lands for crop production resulted in fast surfacing of micronutrient deficiencies in field crops (Shukla et al., 2021) [9] . Organic matter is a key component of soil as its decomposition releases micronutrients in available form to crop. This improves seed germination, crop growth and development. Therefore, assessing the micronutrient status of soil in a region is essential for achieving sustainable crop production (Kavitha C and Sujatha, 2015) [10] . Micronutrients play a vital role in balanced plant nutrition but modern intensive farming using high doses of NPK fertilizers, minimal organic manures and neglecting crop residue recycling has led to the rapid depletion of these nutrients in soil (Shukla et al., 2021) [9] . Since micronutrients are present in small amounts and are poorly available to plants even minor uptake over time can significantly reduce their levels (Takkar, 1996) [11] . The purpose of the present study was to delineate the available Zn, Cu, Fe, Mn, B and Mo status of different locations in Anuppur, Jabalpur, Narsinghpur and Dindori districts of Madhya Pradesh having different cropping systems such as paddy-wheat (cereals -cereals) and paddy-chickpea (cereals -pulses), etc. It also focused on soils treated with fertilizers, organic manures or a mix of both over a continuous period of approximately 3 to 5 years.

Method and Materials

The purpose of this study was to examine the status of available micronutrients of soil in different locations under three different cropping systems. These included: (1) Monocropping with inorganic inputs (paddy, wheat, sugarcane, vegetable pea, pigeon pea); (2) Mixed cropping with inorganic inputs (paddy + wheat and paddy + vegetable pea/ chickpea/ pigeon pea) and (3) Mixed cropping with organic practices (paddy + wheat and paddy + vegetable pea/ chickpea/ pigeon pea). The study area was performed in four targeting districts Anuppur, Jabalpur, Narsinghpur, and Dindori of Madhya Pradesh. In this study, 45 surface soil samples 0-15 cm) were collected from different locations in four districts [Anuppur (15), Jabalpur (10), Narsinghpur (9) and Dindori (11)] of Madhya Pradesh. Geographic coordinates for each sampling site were recorded using a handheld GPS (Geographic Positioning System) device. For each sampling site, five sub-samples of soils were collected. All the collected samples were dried in air under room temperature then ground with the help of a wooden roller and passed through 2 mm stainless steel sieve and stored in labeled cloth bags at room temperature for further analysis of available micronutrients. The samples were taken from the root zone to represent different cropping systems such as monocropping and mixed cropping. Additionally, information on cropping practices and fertilizer use over the last five years was recorded, along with the GPS coordinates (latitude and longitude) of each site (Table 1). To evaluate the available micronutrients status of soils, a comprehensive analysis was perform such as Zn, Cu, Fe and Mn were extracted with 0.005 M DTPΑ having pH 7.3 (Lindsay and Norvell, 1978) [12] and their concentrations were measured using an Atomic Absorption Spectrometer (AAS). However, the available B in soil was estimated by using the hot water extraction method (Berger and Troug, 1939) [13] and color development was done by using azomethine-H reagent (John et al., 1975) [14] . The available Molybdenum content in soil was estimated by grigg's reagent method (Grigg, 1953) [15] .

Results and Discussion

Available Micronutrients (Zn, Cu, Fe, Mn, B and Mo)

The fertility maps representing available micronutrients (Zn, Cu, Fe, Mn, B and Mo) of the surface soil of the different collected sites (villages) of Anuppur, Jabalpur, Narsinghpur and Dindori districts are given in Table 2.

DTPA-Extractable Zinc

The concentration of DTPA-extractable zinc (Zn) in the surface soils from different villages in Anuppur district ranged from 0.48 to 0.60 mg kg -1 , Jabalpur from 0.49 to 0.61 mg kg -1 , Narsinghpur from 0.46 to 0.54 mg kg -1 , and Dindori from 0.46 to 0.54 mg kg -1 with a mean values of 0.54, 0.55, 0.50 and 0.50 mg kg -1 , respectively (Table 2). A total of 45 soil samples, around 40% of the area has low in available Zn, 40% in medium and 20% of high Zn. The deficiency of Zinc at certain sites may be attributed to its continuous removal by crops without adequate replenishment from external sources (Devraj et al., 2020) [16] . These observations are consistent with the findings of Shukla et al. (2014) [17] .

DTPA-Extractable Copper

Available copper (Cu) content of soils showed slight variation among soils collected from villages at different districts, ranging from 0.26-0.32 mg kg-¹ in Anuppur, 0.24-0.29 mg kg-¹ in Jabalpur, 0.25-0.29 mg kg-¹ in Narsinghpur, and 0. [18] reported that the application of chemical fertilizers along with organic manures increased DTPA-extractable Copper compared to the control, whereas the use of chemical fertilizers alone for 36 years led to a decline in Copper content. The increase in available soil Copper over time might be due to accumulation of soluble and exchangeable fractions in the soil profile, as well as the direct release of Copper from farmyard manure (FYM). Inorganic phosphorus fertilizers often contain trace amounts of micronutrients as impurities. Their continuous addition through fertilizers, despite crop uptake and lack of direct replenishment, may have contributed to the observed increase in available micronutrients levels (ElHedek et al. 2014) [19] . The availability of available micronutrients such as Zn, Cu, Fe, and Mn decreases with increasing soil pH. Under alkaline conditions, these micronutrients tend to precipitate or become less soluble. The Cu deficiency may also be linked to the presence of high organic matter, which facilitates Cu complexation with organic compounds, thereby reducing its availability to plants. Similar results of available Cu were reported by Shukla et al. (2015) [20] .

DTPA-Extractable Iron

The content of DTPA-extractable iron (Fe) in soils varied in different villages across districts, ranging from 1.58 to 2.69 mg kg -1 in Anuppur, 1.79 to 2.69 mg kg -1 in Jabalpur, 2.25 to 2.89 mg kg -1 in Narsinghpur, and 1.75 to 3.35 mg kg -1 in Dindori, with corresponding mean values of 2.13, 2.24, 2.57, and 2.55 mg kg -1 , respectively (Table 2). Among the 45 soil samples, about 35.55% of soils fell in the low, 55.55% in the medium, and 8.88% in the high category. The adequate available Fe status at some sites may be due to fluctuations in soil moisture, which strongly influence Fe availability. Improvement in soil pH from continuous urea fertilization may also improve Fe availability (Shukla et al. 2015) [20] . Similarly, Srivastava and Srivastava (1994) [21] reported a 3.9-fold increase in available Fe content in sodic soils under waterlogged conditions compared to field capacity. These results are consistent with the observations of Shukla et al. (2015) [20] . However, the low Fe availability in some soils may be attributed to high pH and moisture stress, which promote the conversion of soluble ferrous iron to less soluble ferric forms (Shukla et al., 2021 [22] ; Sharma et al., 2024 [23] ).

DTPA-Extractable Manganese

The available manganese (Mn) content in soils of different collecting sites varied across districts, ranging from 1.06 to 3.18

mg kg -1 in Anuppur, 1.12 to 3.15 mg kg -1 in Jabalpur, 0.98 to 1.18 mg kg -1 in Narsinghpur, and 1.15 to 1.98 mg kg -1 in Dindori, with mean values of 2.12, 2.13, 1.08, and 1.56 mg kg -1 , respectively (Table 2). As per 45 soil samples analyzed in different villages, 44.44% of soils were classified as low, 35.55% as medium, and 20% as high in available Mn. The low availability of Mn in soils may be attributed to their light texture, which undergoes frequent wetting and drying (Shukla et al. 2015) [20] . Deficiency at some sites could also result from continuous crop uptake without external replenishment (Devraj et al. 2020 [16] ). Moreover, alkaline soil conditions further restrict Mn availability due to reduced solubility at higher pH levels (Sidhu et al., 2009) [24] . Similar results on Mn content was reported in Kaithal district, Haryana (Sharma et al., 2024) [23] . In contrast, sufficient Mn levels at some sites may be due to its release under waterlogged conditions, particularly during rice cultivation (Singh et al., 2009) [25] .

Hot Water Soluble Boron

Hot water soluble boron (B) content showed variation across soils of different collecting sites, ranging from 0.43 to 1.06 mg kg -1 in Anuppur, 0.54 to 1.04 mg kg -1 in Jabalpur, 0.49 to 0.59 mg kg -1 in Narsinghpur, and 0.42 to 0.54 mg kg -1 in Dindori, with mean values of 0.74, 0.79, 0.54, and 0.48 mg kg -1 , respectively (Table 2). Out of 45 soil samples, 77.77% were categorized as low in B, while 22.23% was classified as high. Soil solution pH is recognized as the primary factor regulating B availability (Takkar et al., 1989) [26] . The B availability is lowest at soil pH below 5.0 and between 7.2 and 8.7. Hence, application of lime to acid soils in excessive amounts can sometimes induce B deficiency in plants. In contrast, Fe availability declines with increasing pH, while Mo availability improves under alkaline conditions. Micronutrients availability also shows a positive correlation with organic carbon, particularly in neutral to slightly acidic soils. A similar trend in available B was reported by Shafiq et al. (2008) [27] .

Available Molybdenum

The available molybdenum (Mo) content in soils varied across districts, ranging from 0.018 to 0.049 mg kg -1 in Anuppur, 0.027 to 0.048 mg kg -1 in Jabalpur, 0.035 to 0.044 mg kg -1 in Narsinghpur, and 0.014 to 0.032 mg kg -1 in Dindori, with mean values of 0.033, 0.037, 0.039, and 0.023 mg kg -1 , respectively (Table 2). Among the 45 soil samples, based on soil test ratings, 17.77% of soils were low in Mo, 35.55% in medium, and 46.66% in high. The availability of molybdenum increased significantly with rising soil pH but decreased with higher organic carbon content, while electrical conductivity (EC) showed no significant effect. Similar results were reported by Motos et al. (2024) [28] .

Conclusions

The results revealed widespread deficiencies, which can directly limit crop productivity and threaten long-term soil health. Zinc levels ranged from 0.46-0.61 mg kg⁻¹, with 40% of samples showing low Zn, Copper content varied between 0.22-0.32 mg kg⁻¹ with 15.55% low and Iron ranged from 1.58-3.35 mg kg⁻¹, with 35.55% of soils low in study area. Manganese content was between 0.98-3.18 mg kg⁻¹, with 44.44% low, 35.55% medium, and 20% high. Boron levels (0.42-1.06 mg kg⁻¹) showed the highest deficiency. Molybdenum ranged from 0.014-0.049 mg kg⁻¹, with 17.77% low, 35.55% medium, and 46.66% high.The availability of most cationic micronutrients (Zn, Cu, Fe, Mn) decreased with increasing pH, particularly in alkaline soils. Higher organic carbon content was positively correlated with Zn, Cu, Fe, and Mn availability due to enhanced microbial activity and nutrient chelation. In contrast, B and Mo showed distinct patterns, with B availability being lowest in acidic (<5.0) and moderately alkaline soils (pH 7.2-8.7), and Mo availability increasing with pH. Overall, the findings highlight that micronutrient deficiencies especially Zn, B, and Mn are major constraints to sustainable crop production in the studied regions. These deficiencies are likely linked to intensive cropping, minimal organic matter application, and unbalanced fertilizer use. Regular soil testing, balanced fertilization (including micronutrients), incorporation of organic amendments, and crop diversification are essential to restore soil fertility. Addressing these nutrient gaps will be critical for improving crop yields, maintaining soil health, and ensuring long-term agricultural sustainability in Madhya Pradesh.

Acknowledgement

AcknowledgementThe authors sincerely acknowledge the Department of Biotechnology Centre, and Department of Soil Science and Agricultural Chemistry, College of Agriculture, Jawaharlal Nehru Krishi Vishwa Vidyalaya (JNKVV), Jabalpur (JNKVV) for their generous support. Their valuable assistance, patient guidance and constructive suggestions greatly contributed to the successful completion of this research work. I am also grateful

References

1. Lehmann J, Bossio DA, Kögel-Knabner I, Rillig MC. The concept and future prospects of soil health. Nature Reviews Earth & Environment. 2020;1(10):544-553.
2. Lelago A, Buraka T. Determination of physico-chemical properties and agricultural potentials of soils in Tembaro District, Kembata Tembaro Zone, Southern Ethiopia. Eurasian Journal of Soil Science. 2019;8(2):118-130.
3. Shukla AK, Behera SK. All India Coordinated Research Project on micro-and secondary nutrients and pollutant elements in soils and plants: Research achievements and future thrusts. Indian Journal of Fertilisers. 2019;15(5):522-543.
4. Alloway BJ. Micronutrients and crop production: An introduction. In: Alloway BJ, editor. Micronutrient Deficiencies in Global Crop Production. Dordrecht: Springer. 2008;p.1-39.
5. Singh Y, Raghuvanshi BPS, Tomar R, Verma S, Dubey S. Soil fertility status and correlation of available macro and micronutrients in Chambal region of Madhya Pradesh. Journal of the Indian Society of Soil Science. 2014;62(4):369-375.
6. Shukla AK, Tiwari PK, Prakash C, Tagore GS, Rai HK. Current status of micronutrient deficiencies in soils and crop-specific recommendations for different agro-climatic zones of Madhya Pradesh. Indian Journal of Fertilizers. 2016;12(3):26-35.
7. Dwivedi BS, Dhyan-Singh, Tiwari KN, Swarup A, Meena MC, Majumdar K. On-farm evaluation of SSNM in pearl millet-based cropping systems on alluvial soils. Better Crops-India. 2009;3:25-27.
8. Quddus MA, Anwar MB, Alam MK, Ahmed R, Sarker KK, Islam MA, Islam MT, Kobeasy MI, Gaber A, Ahmed S. Modification of nutrient requirements for a four cropbased cropping system to increase system productivity, maintain soil fertility, and achieve sustainable intensification. Sustainability. 2022;14(12):7194.
9. Shukla AK, Behera SK, Prakash C, Patra AK, Rao CS, Chaudhari SK. Assessing multi-micronutrients deficiency in agricultural soils of India. Sustainability. 2021;13(16):9136.
10. Kavitha C, Sujatha MP. Evaluation of soil fertility status in various agro ecosystems of Thrissur District, Kerala, India. International Journal of Agriculture and Crop Sciences. 2015;8(3):328-338.
11. Takkar PN. Micronutrient research and sustainable agricultural productivity in India. Journal of the Indian Society of Soil Science 1996;44(4):562-581.
12. Lindsay WL, Norvell WA. Development of DTPA soil test for Zn, Fe, Mn and Cu. Soil Science Society of America Journal 1978;42(3):421-428.
13. Berger KC, Troug E. Boron determination in soils and plants. Industrial and Engineering Chemistry Analytical Edition 1939;11(10):540-545.
14. John MK, Chuah HH, Neufeld JH. Application of improved azomethine-H method to the determination of boron in soils and plants. Food and Nutrition Sciences 1975;5(16):287-291.
15. Grigg JL. Determination of available molybdenum in soils. NZ Soil News 1953;3:37-40.
16. Devraj, Antil RS, Garg R, Dahiya DS, Arora VK, Yadav SS, Singh JP. Impact of intensive cropping systems on crop productivity and changes in soil fertility: A case study on benchmark sites of Haryana. Indian Journal of Fertilisers. 2020;16:988-996.
17. Shukla AK, Tiwari PK, Prakash C. Micronutrient deficiencies vis-à-vis food and nutritional security of India. Indian Journal of Fertilisers. 2014;10(12):94-112.
18. Shambhavi S, Bihari B, Kumar R, Verma G, Sharma SP, Sharma K, Sharma RP. Fractions of copper in soil and their contribution to copper availability and uptake in maizewheat cropping system under Typic Hapludalfs. Cereal Research Communications. 2020;48:555-563.
19. El-Hedek KS, El-Kholy MM, El-Tohamy SA. Changes in fractions of some micronutrients as affected by continuous cropping and long-term application of mineral and organic fertilizer. Journal of Soil Sciences and Agricultural Engineering. 2014;5:1247-1268.
20. Shukla AK, Malik RS, Tiwari PK, Prakash C, Behera SK, Yadav H, Narwal RP. Status of micronutrient deficiencies in soils of Haryana. Indian Journal of Fertilisers. 2015;11:16-27.
21. Srivastava AK, Srivastava OP. Response to iron and manganese application as affected by their availability in a Typic Natraqualf. Arid Soil Research and Rehabilitation 1994;8:301-305.
22. Shukla AK, Behera SK, Prakash C, Patra AK, Rao CS, Chaudhari SK, Green A. Assessing multi-micronutrients deficiency in agricultural soils of India. Sustainability. 2021;13:9136.
23. Sharma M, Garhwal RS, Bhardwaj KK, Dubey SK, Kumar A, Singh C, Yadav S. Comprehensive study of nutrient status in Guhla block of Kaithal district, Haryana: Promoting sustainable agriculture. Journal of Soil Salinity and Water Quality. 2024;16:126-140.
24. Sidhu GS, Sharma BD. DTPA-extractable micronutrients status in soil under rice-wheat system and their relationship with soil properties in different agro-climatic zones of Indo-Gangetic Plains of India. Communications in Soil Science and Plant Analysis. 2009;41:29-51.
25. Singh VK, Agrawal HP, Prasad S. Distribution of DTPAextractable micronutrients in the soils of district Ghazipur, Uttar Pradesh. Journal of the Indian Society of Soil Science. 2009;57:370-372.
26. Takkar PN, Chibba IM, Mehta SK. Twenty years of coordinated research on micronutrient in soils and plants. Bulletin 314. Indian Institute of Soil Science, Bhopal 1989;p.81.
27. Shafiq M, Ranjha AM, Yaseen M, Mehdi SM, Hannan A. Comparison of Freundlich and Langmuir adsorption equations for boron adsorption on calcareous soils. Journal of Agricultural Research. 2008;46(2):141-148.
28. Matos C, Montenegro R, Uchôa S, Júnior J, Saboia V, Tavares I. Soil micronutrients: dynamics, availability, and fertilization management. SEVEN Academic Publication. 2024.