Soil biochemical changes at different wheat growth stages in response to conservation agriculture practices in a rice-wheat system of north-western India

Abstract

Intensive tillage, removal or burning of crop residues, limited organic manure use, declining irrigation water resources and scarcity of labour are the major causes of soil degradation and unsustainability of rice (Oryza sativa L.)–wheat (Triticum aestivum L.) system (RWS) in South Asia.Resource conservation technologies (RCTs) such as zero tillage (ZT), dry direct seeded rice (DSR) and crop residues retained as mulch have shown promise to increase the productivity and profitability of RWS in South Asia. Effects of RCTs on soil biological parameters are unclear and contradictory. We evaluated the effects of conservation agriculture practices on changes in soil biochemical properties at different growth stages of wheat grown as the fifth crop in RWS. Twelve treatment combinations of tillage, crop establishment and crop residue management included four main plot treatments in rice: (1) conventional tillage (CT)-DSR,(2) ZT-DSR, (3) DTR, ZT machine transplanted rice and (4) PTR, conventional puddled transplanted rice. The three subplot treatments were: (i) CTW-R, CT wheat with both rice and wheat residues removed, (ii) ZTW-R, ZT wheat with residues of both the crops removed and (iii) ZTW+R, ZT wheat with rice residue retained as surface mulch in subsequent wheat. Irrespective of rice establishment methods, mean wheat grain yield under ZTW+R was 6% and 10% greater than CTW-R and ZTW-R respectively. Soil enzyme activities increased (5–18%) under ZTW+R compared with ZTW-R and CTW-R at different growth stages of wheat. The residual effect of rice establishment methods was significant on soil enzyme activities during wheat cropping, which were highest under ZT-DSR followed by CT-DSR, DTR and PTR. Soil organic carbon content in the 0–7.5 cm layer was significantly higher (7–9%) under the ZTW+R treatment compared with all the other treatments. Principal component analysis (PCA) identified three enzyme activities (dehydrogenase, fluorescein diacetate and phosphatase), and soil organic carbon content as the most sensitive indicators for assessing soil quality for RWS based on conservation agriculture. The PCA discriminated rice establishment systems with rice residue as surface mulch from rice establishment systems without rice residue and the maximum tillering stage from the other stages of wheat. The present study provided reliable biochemical indicators to monitor soil biological quality changes in response to conservation agriculture practices in RWS.

Climate smart agriculture influences soil enzymes activity under cereal-based systems of north-West India

“…A particular trend of ARS activity was recorded irrespective of scenarios, highest at tillering and lowest at harvesting, it may be due to the effect of crop growth stage. Such type of result is also reported by Bera et al (2017) who reported higher enzyme activity at the vigorous vegetative growth stages (such as maximum tillering and jointing stages) than at the reproductive growth stages (such as grain filling and maturity stages). It was 14 per cent higher in CSA systems (Sc2-Sc6) than farmer's practice.…”

Nutrient removal by rice–wheat cropping system as influenced by crop establishment techniques and fertilization options in conjunction with microbial inoculation

“…The soil microbial properties respond quickly and significantly to change in tillage 61 , crop establishment techniques 29 , 62 , fertilization 63 and external inoculation of microbial culture 64 . In the present study, microbial consortia involving cyanobacteria for nitrogen fixation and bacteria for P solubilization were used.…”

“…These CETs have varied levels of impact on soil properties, plants performance and nutrient and water availability 3 , 28 , 29 . Such impacts can act as a guide for modulating the recommendations and input portfolio of crop and/or cropping system.…”

Tillage, Green Manure And Residue Retention Improve Aggregate-Associated Phosphorus Fractions Under Rice-Wheat Cropping

“…To address the aforementioned issues, conservation agriculture (CA)-based practices (minimum tillage, residue retention and crop diversi cation) are being developed and promoted for rice and wheat production (Gathala et al, 2013). The alternative systems of tillage, green manure (GM) and residue management practices under CA-based practices can potentially lead to signi cant changes in the availability of nutrients in RWS (Bera et al, 2017;Saikia et al, 2019a). The CA-based practices holds the potential to enhance P availability by altering the soil microbial diversity and enzyme activity, which in turn affects the availability of soil P (Wang et al, 2011;Bhan and Behera 2014;Bezerra et al, 2015).…”