Zero Tillage Plus Residue Management and K Fertilization Effect on Cotton Yield and K Use Efficiency in Wheat-Cotton System

Abstract

Zero tillage straw retained with optimum K is an important strategy to increase cotton ( Gossypium hirsutum L.) yield and K efficiency in wheat ( Triticum aestivum L.)-cotton system. A 2 years field experiment was conducted during 2018, and 2019 to study the impact of [zero tillage straw as such on soil surface (ZT SAS ) and zero tillage straw burnt (ZT SB )] and five K rates were 0, 20, 40, 60 and 80 kg ha -1 on cotton yield and K use efficiency. Results indicated that bolls/plant –1 , weight per boll, seed cotton yields, ginning out turn and K agronomic efficiency were highest with 60-80 kg K ha –1 . Interactions revealed that ZT SAS with 60-80 kg K ha –1 had higher bolls/plant, bolls weight, seed cotton yields and ginning out turn compared to ZT SB . K agronomic efficiency indices decreased with increasing K rate. ZT SAS with 20 kg K ha –1 gave greater K agronomic efficiency than other combinations. ZT SAS with 60-80 kg potassium per hectare may be a sustainable and environmentally safe strategy to enhance cotton yield and soil fertility . from combined input of ZT with straw retained and k fertilizer application at 60 kg K ha -1 . This shows that retention of crop residues has led to the increase in the K contents of soil and microbial activity which is clear indication of an improvement in soil health (Pankhurst et al. 2002; Nie et al. 2007). In the present study, we tried to optimize K management under zero tillage methods in order to improve cotton yield in wheat-cotton system.