Crop residue incorporation combined with potassium fertilizer increased cotton canopy apparent photosynthesis and seed cotton yield in barley-cotton rotation system

Abstract

The field experiment was conducted to evaluate the effects of crop residue incorporation and K fertilizer on seed cotton yield, K uptake and canopy apparent photosynthesis. Without K fertilizer, barley residue incorporation and barley-cotton residue incorporation increased seed cotton yield, total biomass, K uptake, leaf K concentration, leaf area index and canopy apparent photosynthesis in 2017 and 2018, while cotton residue incorporation increased these factors in 2018 and with 150 kg ha−1 K2O, barley residue incorporation and barley-cotton residue incorporation increased K uptake and leaf K concentration in 2017 and 2018, while these factors were influenced by cotton residue incorporation in 2018. Thus, the effects of crop residue incorporation on cotton growth depended on K fertilizer rate. In addition, crop residue incorporation could reduce K fertilizer input to some extent. Based on yield, barley residue incorporation and barley-cotton residue incorporation could reduce 73.7 kg ha−1 K2O (49.1%) and 70.1 kg ha−1 K2O (46.7%) in 2017, 53.6 kg ha−1 K2O (35.7%) and 89.5 kg ha−1 K2O (59.6%) in 2018, while cotton residue incorporation could reduce 38.0 kg ha−1 K2O (25.4%) in 2018.