Main content area

Integrated phosphorus management in maize-chickpea rotation in moderately-alkaline Inceptisol in Kanpur, India: An agronomic and economic evaluation

Venkatesh, M.S., Hazra, K.K., Ghosh, P.K., Mishra, J.P.
Field crops research 2019 v.233 pp. 21-32
Inceptisols, alkaline soils, animal manures, bacteria, chickpeas, corn, costs and returns, crop rotation, economic evaluation, field crops, field experimentation, grain yield, mineral fertilizers, pH, phosphates, phosphorus, profitability, residual effects, seed treatment, tropical soils, India
Worldwide, input-intensive modern agriculture is accountable for incessant depletion of non-renewable phosphorus (P) reserve. This, in turn, has generated a renewed interest on efficient use of fertilizer P in field crop production, which is equally important for enhancing profitability and mitigating environmental challenges associated with fertilizer P application. In tropical soils, the productivity of field crops is mostly constrained by low availability of P in soil. Given the context, a field experiment was carried out on a moderately-alkaline Inceptisol (pH ˜8.2) for five years to assess the effect of six system-based inorganic fertilizer P treatments (kg P2O5 ha−1) in maize (M)-chickpea (C) rotation [M0-C0, M0-C40, M30-C0, M30-C40, M60-C0, M60-C40], two manure treatments [no farmyard manure (FYM), FYM at 5 t ha−1] and two phosphate solublizing bacteria (PSB) treatments [no treatment, PSB seed treatment in chickpea] on crop performance, system productivity, economics and production sustainability. A strong integrated effect of FYM and fertilizer P was observed on growth and productivity of both the component crops. However, the effect of PSB was marginal. Notably, the treatment M30-C0+FYM had a similar maize yield to that of M60-C40-FYM; and, chickpea grain yield was comparable in the treatments M60-C0+FYM ± PSB and M60-C40-FYM ± PSB, indicating a strong positive effect of FYM in alkaline soil, which was primarily attributed to increased soil available-P. At the end of five-year rotation, soil available-P in absolute control treatment M0-C0-FYM-PSB was depleted by 53%, where an increase of 56% in available-P was observed in the treatment M60-C40+FYM + PSB. In both the component crops, strong correlations (p < 0.01) between grain yields and soil available-P were observed. Residual effect of fertilizer P was observed in the subsequent crop, being higher in chickpea. The scale of residual advantage of fertilizer P was decreased with increase in current fertilizer P rate. Irrespective of FYM and PSB treatments, order of fertilizer P treatments for chickpea equivalent yield (CEY) was M60-C40 > M30-C40 > M0-C40 ≥ M60-C0 > M30-C0 > M0-C0 (p < 0.05). The treatment M60-C40+FYM + PSB led to 18% higher CEY over the treatment M60-C40-FYM-PSB, which in turns fetched additional net returns of INR 14,853. Thus, integrated application of FYM (5 t ha−1) and fertilizer P treatment M30-C40 could be recommended for higher crop productivity and economic return from maize-chickpea rotation in tropical moderately-alkaline soil.