Tillage, green manure and residue retention improves aggregate-associated phosphorus fractions under rice–wheat cropping

Abstract

The sustainability of the rice–wheat system is threatened due to the deterioration of soil health and emergence of new challenges of climate change caused by low nutrient use efficiency and large scale burning of crop residues. The conservation agriculture based on tillage intensity, crop residue retention and raising green manuring (GM) crops during the intervening period between wheat harvest and rice establishment offers opportunities for restoration of phosphorus (P) dynamics and stimulate phosphatase activities within the macro-and micro-aggregates. Phosphorus and phosphatase activities in the soil aggregates affected by different residue management practices remain poorly understood. Thus, soil samples were obtained after a five-year field experiment to identify the effect of tillage, green manure and residue management on aggregate-associated phosphorus fractions. Four main plot treatments in rice included combination of wheat straw and GM were conventional till puddled transplanted rice (PTR) with no wheat straw (PTRW0), PTR with 25% wheat stubbles retained (PTRW25), PTR without wheat straw and GM (PTRW0 + GM), and PTR with wheat stubbles and GM (PTRW25 + GM). Three sub-plots treatments in the successive wheat crop were conventional tillage (CT) with rice straw removed (CTWR0), zero tillage (ZT) with rice straw removed (ZTWR0) and ZT with rice straw retained as surface mulch (ZTWR100). Results of the present study revealed significantly higher phosphorus fractions (HCl-P, NaHCO3-Pi and NaOH-Po) in treatment PTRW25 + GM and ZTWR100 compared with PTRW0/CTWR0 within both macro- and micro-aggregates. The total phosphorus (P), available P, alkaline phosphatase and phytin-P were significantly higher under ZTWR100 than CTWR0. The principal component analysis identified NaOH-Po, NaHCO3-Pi and HCl-P as the dominant and reliable indicators for evaluating P transformation within aggregates under conservation agriculture-based practices.

Influence of tillage and residue management practices on productivity, sustainability, and soil biological properties of rice-barley cropping systems in indo-gangetic plain of India

“…As a result of the long-term crop residue management techniques, the soil's microbial population and biomass C or N significantly increased, giving energy and an ideal environment for the development of soil enzymes (Xomphoutheb et al, 2020 ). In this study, alkaline phosphatase enzymes were found high in residue-incorporated treatments, which is in accordance with earlier studies (Gupta et al, 2022 ; Sharma et al, 2022a ). However, NR is the enzyme that catalyzes the reduction of to in soil and also represents nitrogen immobilization (Canfield et al, 2010 ; Grzyb et al, 2021 ).…”

“…The three main principles of conservation agriculture (CA) (minimum soil disturbance, crop diversification, and permanent soil cover) contribute to protecting the soil from erosion and degradation, improving soil quality and biodiversity, preserving the natural resources, and increasing their use efficiency, optimizing crop yields, while imparting environmental sustainability (Sharma et al, 2022a ). Conservation tillage (CT), such as no-tillage or reduced tillage, decreases soil disturbance, protects the soil against erosion, and increases soil organic matter (Busari et al, 2015 ).…”

Changes in Wheat Rhizosphere Carbon Pools in Response to Nitrogen and Straw Incorporation

“…They reported higher CO 2 emission due to the additional contribution of microbial decomposition of root exudates in straw followed by surface application compared to in the no-residue treatment. Straw return promotes the metabolic activity of micro-organisms, the relevant enzyme activity, and microbial population, which enhanced the nutrient availability in the soil [13,22]. The results in the present study are consistent with those of Samuelson et al [62], which indicate that N fertilization increased the BSR and MBC, but the effect on soil respiration was non-significant.…”

“…Rice straw is a source of soil organic carbon (SOC) that plays an important role, adding soil cover that can result in improving soil structure, water use efficiency, nutrient use efficiency, and soil microbial diversity [11]. It provides energy as well as substrates for microbial activity and biological diversity and enhances soil biological activities [12,13]. Moreover, changes in SOC are highly associated with the active soil labile carbon (C), which is primarily based on soil biological activities.…”

Ecological Role of Different Siderate Crops in Improving Soil Properties

“…S.Sharma and others [5] experimentally studied the enrichment of the soil with phosphorus and organic residues and the increase in the number of waterresistant microaggregates as a result of planting siderate crops.…”