Elucidating the impact of boron fertilization on soil physico-chemical and biological entities under cauliflower-cowpea-okra cropping system in an Eastern Himalayan acidic Inceptisol

Abstract

Information on the role of boron (B) on soil physico-chemical and biological entities is scarce, and the precise mechanism in soil is still obscure. Present field investigation aimed to assessing the implication of direct and residual effect of graded levels of applied-B on soil biological entities and its concomitant impact on crop productivity. The treatments comprised of five graded levels of B with four replications. To assess the direct effect of B-fertilization, cauliflower was grown as a test crop wherein, B-fertilization was done every year. For assessment of succeeding residual effects of B-fertilization, cowpea and okra were grown as test crops and, B-fertilization was phased out in both crops. The 100% recommended dose of NPK (RDF) along with FYM was uniformly applied to all crops under CCOCS. Results indicated that the direct effect of B had the edge over residual effect of B in affecting soil physico-chemical and biological entities under CCOCS. Amongst the graded levels of B, application of the highest B level (2 kg ha–1) was most prominent in augmenting microbiological pools in soil at different crop growth stages. The order of B treatments in respect of MBC, MBN, and soil respiration at different crop growth stages was 2.0 kg B ha–1 > 1.5 kg B ha–1 > 1.0 kg B ha–1 > 0.5 kg B ha–1 > 0 kg B ha–1, respectively. Moreover, maximum recoveries of potentially mineralizable-C (PMC) and potentially mineralizable-N (PMN) were noticed under 2 kg B ha–1. Analogous trend was recorded in soil microbial populations at different crop growth stages. Similarly, escalating B levels up to 2 kg B ha–1 exhibited significantly greater soil enzymatic activities viz., arylsulphatase (AS), dehydrogenase (DH), fluorescein diacetate (FDA) and phosphomonoesterase (PMA), except urease enzyme (UE) which showed an antagonistic effect of applied-B in soil. Greater geometric mean enzyme activity (GMEA) and soil functional diversity index were recorded under 2 kg B ha–1 in CCOCS, at all crop growth stages over control. The inclusive results indicated that different soil physico-chemical and biological properties CCOCS can be invariably improved by the application of graded levels of B up to 2 kg B ha–1 in an acid Inceptisol.

High-value crops’ embedded groundnut-based production systems vis-à-vis system-mode integrated nutrient management: long-term impacts on system productivity, system profitability, and soil bio-fertility indicators in semi-arid climate

“…The legume–legume crop rotation (GFCS) had significantly higher levels of SMBC and SMBN compared to legume–non-legume rotations (GWCS and GMCS) ( Figure 5 ). The practice of crop rotation has been observed to alter the status of soil nutrients through microbial immobilization ( Balota et al., 2003 ; Bhupenchandra et al., 2022a ; Bhupenchandra et al., 2022c ). In this study, the highest SOC was noted for the GFCS.…”

“…The highest SMBC (201 µg/g of dry soil) and SMBN (27.9 µg/g of dry soil) were obtained when 5 t/ha LCMC+RDF 50 was applied to groundnut. Higher microbial count in manure compost could likely be the reason for these higher values ( Bana et al., 2012 ; Bhupenchandra et al., 2022a ). Compared to F50, the F100 improved both SMBC and SMBN in the study.…”

“…Microbial activity in soil is mostly correlated with available SOM ( Zhong and Cai, 2007 ). Microbes primarily feed on SOM and make several nutrients available to plants, which are produced as their metabolic by-products, among which carbon and nitrogen are especially of importance for plant growth ( Perelo and Munch, 2005 ; Six et al., 2006 ; Bhupenchandra et al., 2022a ; Bhupenchandra et al., 2022c ). Microbes, while feeding on SOM, also release many biostimulants and hormones, which again help in enhancing plant growth and productivity ( Bhupenchandra et al., 2022c ; Rajanna et al., 2023 ).…”

“…Moreover, the inclusion of organics under nutrient management programs ensures a smooth supply of micronutrients as well as major nutrients ( Bana et al., 2018 ; Rajpoot et al., 2021 ). The usage of organics also bestows a favorable micro-environment for crop growth and development, principally by improving soil properties ( Bana et al., 2012 ; Bana et al., 2016 ; Bana et al., 2018 ; Bhupenchandra et al., 2022a ).…”

“…Moreover, the soil biological functions are enormously dynamic and extremely sensitive to agronomic management practices like cropping system diversification ( Yusuf et al., 2009 ), nutrient management ( Liu et al., 2010 ; Bana et al., 2015 ; Ghosh et al., 2017 ), residue recycling, and crop establishment methods ( Srinivasarao et al., 2013 ; Naragund et al., 2020 ; Harish et al., 2022a ). Therefore, it is crucial to have deeper insights and understanding of the effect of diverse cropping systems and contrasting nutrient management practices on SMBC, SMBN, and soil microbial enzymatic activities for designing more appropriate and economically and ecologically sound management practices for the long-term sustainability of food systems ( Bhupenchandra et al., 2022a ).…”