Trends in key soil parameters under conservation agriculture-based sustainable intensification farming practices in the Eastern Ganga Alluvial Plains

Abstract

Key soil parameters, organic matter, soil pH and plant nutrients determine the capacity of a soil to sustain plant and animal productivity. Conservation agriculture (CA) and crop diversification or intensification may change these soil parameters positively or negatively, which eventually affect long-term sustainability. We monitored these key soil properties (at depths of 0–15 and 15–30 cm) under CA-based sustainable intensification practices: zero-till (ZT), and crop residue retention, and crop rotations on Inceptisols and Entisols in the Eastern Ganga Alluvial Plains from 2014 to 2017. The rainfall of this sub-tropical region is 1273–3201 mm. Soil organic carbon (C) ranged within 0.46–1.13% and generally followed (positive) rainfall gradients. At all sites, the soil under ZT tended to have higher organic C than conventional tillage (CT). Soil pHH2O ranged within 5.7–7.8 across the region. At all sites, soil pH generally decreased under ZT compared to CT. This was most marked at some acidic soil sites where pH decreased by up to 0.4 units; the lower the initial soil pH, the higher was the decrease in pH under ZT practice. In contrast, the reverse trend was observed for soil organic C. Partial nutrient balances for N, P and K in rice–wheat and rice–maize systems were positive for N and P (<50 kg ha–1) but negative for K (up to 90 kg ha–1) under both tillage practices; more so under ZT practice even though crop residues were retained. Changes under ZT provide an opportunity to maintain soil organic C. However, remediation measures such as liming and efficient use of fertilisers are required for long-term sustainability of the farming systems in this agriculturally important region of South Asia.

Vertical Distribution of TOC, TN and Other Important Soil Attributes and Their Relationship in Alfisol and Entisol of West Bengal

“…The Entisols of Cooch Behar fall under Terai agro-ecological region [16]. Here, organic C lies between 0.30-1.69% [17]. A clear understanding of the depth-wise distribution of soil fertility indicators like TOC, TN, and other important properties and their relationship is imperative in these soils.…”

Application of innovation platforms to catalyse adoption of conservation agriculture practices in South Asia

“…This paper builds on other work in the EGP through the SRFSI project (Brown et al, 2020;Gathala et al, 2020a;Gathala et al, 2020b;Gathala et al, 2021;Islam et al, 2019;Sinha et al, 2019). Districts were originally selected because they are considered as typical marginal areas with a range of constraints (Islam et al, 2019), but they were also matched in pairs across country borders to enable comparison of similar physical conditions (soil type, rainfall, ground water resources), but with different socioeconomics and institutional settings (e.g., comparison of Rangpur, Northwest Bangladesh with Coochbehar, West Bengal, India) (Figure 1).…”

“…SRFSI focused on raising the productivity of the rice-, wheat-and maize-based farming systems characteristic of the EGP with Conservation Agriculture (CA) practices. Farm mechanization has been a strong focus, specifically the introduction of CA machinery which reduces inputs (labour, water, seed) while improving soil fertility by retaining and planting into crop residues (Gathala et al, 2020a;Gathala et al, 2020b;Islam et al, 2019;Sinha et al, 2019). This strategy is referred to as Sustainable Intensification (SI).…”

Soil Chemical Properties under Conservation Agriculture and Cereal-Based Cropping System in Eastern Tarai of Nepal

“…Responses to K and/or Zn were observed for both rice and wheat, but these varied as a function of soil texture and between years. The soil under ZT found containing less available K than CT at Regional Agricultural Research Station, Tarahara (Sinha et al 2019). Furthermore, negative K balance for crops in South Asia is widespread (Singh et al 2005, Surekha andSatishkumar 2014).…”

“…Soil parameters like organic matter, soil pH and plant nutrients determine the capacity of soil to sustain crops productivity. Conservation agriculture (CA) and crop diversification or intensification may change these soil parameters positively or negatively, which eventually affects long-term sustainability (Sinha et al 2019). Key soil parameters such as soil organic matter, pH and plant nutrients reflect both inherent and dynamic soil properties, and are governed by physical, chemical and biological processes in soil (Karlen et al 2003).…”