Maximizing Sugarcane Yield by Increasing Plant Population Density, Minimizing NO3‐N Leaching and Improving Soil Organic Matter in Different Crop Rotations

Abstract

AbstractIn a field experiment conducted during 1992–95 at Lucknow, India, sugarcane was planted in rows 60 and 90 cm apart in three crop rotations (rice‐sugarcane‐ratoon, Sesbania aculeata for green manure‐sugarcane‐ratoon, and cowpea‐sugarcane‐ratoon) with 0, 150 and 300 kg N ha−1 as urea either with or without farmyard manure (FYM) at 10 t ha−1. Sugarcane yields were significantly greater in the Sesbania rotation than in the other because of a larger N uptake. N uptake of the crop was significantly affected by soil organic carbon, and available N and K contents. Ratoon yields, however, were largest in the cowpea sequence followed by the rice rotation, probably due to a prolonged residual effect of cowpea and rice root residues. The residual effect of a Sesbania green manure was negligible as demonstrated by the low NO3‐N content of the soil profile after sugarcane harvest compared to the other two crop sequences. The total cane productivity (main sugarcane plus ratoon) was greater (156 t ha−1) in the cowpea rotation than the Sesbania (152 t ha−1) and rice (140 t ha−1) rotations.