Molecular Soil Biology 2025, Vol.16, No.6, 314-324 http://bioscipublisher.com/index.php/msb 317 Figure 1 Mean of nutrients for inputs and outputs, and the principles of integrated nutrient management systems (Adopted from Sharma et al., 2019) 4.2 Nutrient management based on soil testing and field differences In a 36-year INM trial of rice-wheat in eastern India, compared to the treatment with 100% RDF in both rice and wheat seasons, the treatment with 50% RDF + 50% nitrogen replaced by FYM throughout the entire season resulted in a 46.4% increase in wheat soil organic carbon content (an increase of 18.29 Mg ha-1), an annual average carbon sequestration rate of 0.22 Mg ha-1 yr-1, and significant improvements in the agronomic efficiency of nitrogen, phosphorus, and potassium, as well as the productivity of some factors. When 50% RDF + 50% FYM replaced 100% RDF alone during the wheat season, wheat grain yield increased by 24.7%, while greenhouse gas emission intensity decreased significantly (Ranjan et al., 2023). In a dryland maize-wheat system in North India, 17 years of INM treatment (fertilizer combined with FYM) increased organic carbon in the 0~15 cm soil layer from 0.44% to 0.66%, while available N, P, and K increased to 164.9, 31.4, and 168.0 kg/ha, respectively. DTPA-based treatment also significantly increased available Zn, Cu, Fe, and Mn, while decreasing soil pH, EC, and bulk density, and increasing water holding capacity and total porosity (Dhaliwal et al., 2021). In a sensor-variable nitrogen application study involving 57 fields, canopy sensor-based N management reduced nitrogen use efficiency by an average of 40 kg N ha-1 in maize without yield reduction, significantly improving nitrogen use efficiency. However, the increase in efficiency in wheat was not statistically significant and was strongly controlled by field yield level, yield spatial variability, and soil texture (Paccioretti et al., 2025). 4.3 Conservation agriculture and crop residue management Under wide-ridge no-till farming, wheat shows better root growth when the soil surface is fully covered by crop residues. When the full recommended nitrogen rate is applied together with residue retention (PBB + R + 100N), wheat root length density increases a lot. It is about 60% higher than that under traditional tillage. At the same time, the total yield of the three-crop system also goes up clearly. The increase reaches about 31.1%. When nitrogen input is reduced to 75% of the recommended level, but crop residues are still kept on the field, crops use nutrients more efficiently. In this case, the use efficiency of nitrogen, phosphorus, and potassium is even higher than with full nitrogen input (Ghosh et al., 2025). In long-term rice–wheat nutrient management systems, part of the straw is returned to the soil. About one-third of wheat straw or one-third of rice straw is added back during the rice season. Nitrogen fertilizer is then applied at levels ranging from 55% to 100% of the recommended rate. As a result, nitrogen supply during the wheat season increases clearly. It reaches 649 μg cm-2 with wheat straw and 687 μg cm-2 with rice straw. Under these conditions, wheat nitrogen use efficiency improves strongly, increasing by about 1.3 to 2.0 times (Bhardwaj et al., 2021). 4.4 Integration with crop rotation and intercropping systems In a 40-year long-term rice-wheat trial, treatments using 50% RDF + 50% FYM (or combined with wheat straw and green manure Sesbania) during the rice season and 100% RDF during the wheat season resulted in a wheat grain yield of 4435 kg/ha (Manohar et al., 2025). In the maize-wheat system, a nitrogen management strategy
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