Long‐Term Effects of Organic Inputs on Yield and Soil Fertility in the Rice–Wheat Rotation

Abstract

The sustainability of the rice (Oryza sativa L.)–wheat (Triticum aestivum L.) rotation is important to Asia's food security. Intensive cropping with no return of crop residues and other organic inputs result in the loss of soil organic matter (SOM) and nutrient supply, and is assumed to be nonsustainable. We evaluated seven treatments comprised of various combinations of green manure (GM; Sesbania cannabina L.); wheat straw (WS), farmyard manure (FYM), and urea on yields and yield trends; P and K balance; and soil fertility in a rice–wheat experiment (1988–2000) on a loamy sand in Punjab, India. Rice yields were comparable with GM + urea, WS + GM + urea, and urea alone, but yields were reduced when FYM was supplemented with N. Except during 1 yr, integrated use of FYM and GM produced equal or higher rice yields than other GM based treatments. Wheat straw incorporation reduced average rice yields by 7% compared with WS removal. After 5 yr of continuous application, FYM and WS were at par in increasing rice yields. Organic materials applied to rice had no residual effect on wheat yields except FYM, which increased yield by about 6% compared with urea alone. Rice yield declined by 0.02 to 0.13 Mg ha−1 yr−1 but wheat yields remained unchanged. Soil C increased with the application of WS and FYM. Potassium balance was highly negative. Although the causes of yield decline are unknown, inadequate K applications and changes in the climatic parameters are possible reasons.

Long-term effects of manure application on grain yield under different cropping systems and ecological conditions in China

“…There have been concerns that soil degradation threatens the sustainability of cropping systems (Duxbury et al 2000; Yadav et al 2000 a ; Timsina & Connor 2001; Bhandari et al 2002; Ladha et al 2003; De Costa & Sangakkara 2006; Ghosh et al 2006; Taylor et al 2006). Use of manures is generally seen as a key practice for maintaining soil fertility and agricultural sustainability in the wheat–maize rotation and rice-based cropping systems (Yadav et al 2000 a , b ; Bhandari et al 2002; Regmi et al 2002; Ladha et al 2003; Sarkar et al 2003; Saleque et al 2004; Yadvinder et al 2004; Jiang et al 2006). The application of manure not only provides extra organic carbon and major nutrients such as nitrogen (N), phosphorus (P) and potassium (K), but also improves soil physical and chemical properties (Yadav et al 2000 b ; Bhandari et al 2002).…”

Potassium transformation in clay soil with contrasting K budgets in long‐term experiment

“…While K is directly taken up by plants in the form of K + in soil solution, instantaneous reserves of readily available dissolved K meet only 5% of total crop K requirements (McLean & Watson, 1985). Because insufficient K supply rate could decrease crop yield (Regmi et al, 2002;Yadvinder-Singh et al, 2004), adequate K fertilization can enhance the productivity of cereals (Regmi et al, 2002) and forage crops such as alfalfa (Medicago sativa L.; Malhi, Gill, McCartney, & Malmgren, 2004). However, plant response to K fertilization depends on soil texture, crop types (Bailey, 1983;Öborn et al, 2005), soil K status (Zhang et al, 2011), and soil clay content (Wakeel, Gul, & Sanaullah, 2013).…”

“…The K budget at field scale (Benbi & Biswas, 1999; Yadvinder‐Singh et al., 2004; Yang, Sun, & Zhang, 2014) and soil K test (Mallarino, Barbagelata, & Wittry, 2004; Yang et al., 2014) or estimated exchangeable K are often used to manage K over large agricultural areas (Bailey, 1983; Tan, Jin, Jiang, Huang, & Liu, 2012). While soil test critical K levels depend on clay mineralogy (Breker et al., 2019), the contribution of non‐exchangeable K (Hinsinger, 2002; Lal, Swarup, & Singh, 2007; Rupa, Srivastava, Swarup, & Singh, 2001) or interlayer K (Hinsinger & Jaillard, 1993; Øgaard & Krogstad, 2005) to plant K uptake may be substantial.…”

Implications of humic, fulvic and K-humate extracted from each of compost and biogas manure as well as their teas on faba bean plants grown on Typic Torripsamments and emissions of soil CO2

“…Agriculture is the capital of human civilization (Scotti et al, 2015). The shocking news is that hunger is increasing nowadays (Weis, 2007). This is because of the increasing demands for plant production to meet the concurrent increases in human population (Weber, 1999).…”