Comparative assessment of soil biological health and productivity under natural, organic and integrated cropping system

Abstract

Sustainable nutrient management practices are essential for maintaining crop productivity while improving soil biological health and ecosystem functioning. However, information on comparative assessment between crop productivity and soil biological functioning under natural, organic, and integrated farming systems in diversified cropping systems of the Central Himalayan foothills remains limited. Therefore, a field experiment was conducted during 2022–24 under a maize + fodder cowpea–wheat + chickpea cropping system in the foothills of the Central Himalayas to evaluate the effects of natural farming (NF), organic farming (OF), integrated crop management with botanical pesticides (ICM-B), integrated crop management with chemical pesticides (ICM-C), and a control treatment ( Sesbania alone) on crop productivity, soil microbial populations, enzymatic activities, and microbial biomass dynamics. The results revealed significant (p < 0.05) differences among nutrient management practices. Among the treatments, ICM-B recorded the highest maize grain yield (4838 and 5008 kg ha - ¹) and wheat grain yield (1791 and 1802 kg ha - ¹) during 2022–23 and 2023–24, respectively, remaining statistically comparable with ICM-C. Similarly, chickpea grain yield was maximum under ICM-B (1086 and 1109 kg ha - ¹). In contrast, OF consistently enhanced soil biological properties. The highest bacterial population (23.51 × 10 6 and 31.05 × 10 6 CFU g - ¹ soil), fungal population (6.85 × 10³ and 6.30 × 10³ CFU g - ¹ soil), and actinomycetes population (19.88 × 10 4 and 23.38 × 10 4 CFU g - ¹ soil) were recorded under OF during Kharif and Rabi seasons, respectively. Organic farming also exhibited superior enzymatic activities, including urease (40.76 and 39.68 µg urea g - ¹ soil h - ¹), dehydrogenase (123.39 and 116.58 µg TPF g - ¹ soil 24 h - ¹), alkaline phosphatase (106.97 and 95.85 µg PNP g - ¹ h - ¹), and acid phosphatase (113.12 and 105.34 µg PNP g - ¹ h - ¹), along with higher microbial respiration, microbial biomass carbon, and microbial biomass nitrogen. Correlation analysis demonstrated strong positive relationships among microbial populations, enzymatic activities, microbial biomass parameters, and soil respiration, indicating the close linkage between soil biological functioning and nutrient cycling processes. Although NF and OF resulted in lower crop productivity than integrated management practices, the substantial improvements in soil biological health indicate their potential to enhance long-term soil resilience, nutrient-use efficiency, and ecosystem sustainability. Overall, ICM-B proved most effective in maximizing crop productivity, whereas OF significantly improved soil microbial abundance, enzymatic activity, and biological health. These findings demonstrate that integrating organic resource management with sustainable nutrient management practices can support climate-smart agriculture by enhancing productivity, strengthening soil resilience, and promoting long-term sustainability of cropping systems in the Himalayan foothill region.