Improving maize productivity through tillage and nitrogen management
Continuous cultivation of fields with same implement (cultivator) creates a hard pan in the subsoil which adversely affects crop productivity. In addition to tillage, nitrogen management is a key factor for better crop growth and yield. Impact of different tillage systems and nitrogen management on yield attributes and grain yield of hybrid maize was evaluated by conducting experiments at the Agronomic Research Area, University of Agriculture, Faisalabad during 2008 and 2009. The experiment comprised of three tillage systems viz. conventional tillage, tillage with mould board plough followed by 2-cultivations (with cultivator), tillage with chisel plough followed by 2-cultivations (with cultivator) and three nitrogen levels (100, 150 and 200 kg ha-1). Different tillage systems and nitrogen levels significantly influenced the maize yield and yield components. Chisel ploughed plots resulted to heavier cobs, higher 1000-grain weight and grain yield in comparison with other tillage systems. Maize yield with chisel tilled plots was 18 and 9% higher than mould board ploughed and conventionally tilled plots, respectively. Generally, differences between different nitrogen application rates were more pronounced; increasing nitrogen rate resulted in increased yield and yield components of maize. Significantly, highest grains weight per cob, 1000-grain weight and grain yield was recorded with 200 kg ha-1 nitrogen application. Maize yield with 200 kg ha-1 nitrogen application was 17 and 8.50% higher than 100 and 150 kg ha-1 nitrogen application, respectively. Therefore, it may be concluded that maize hybrids should be grown with 200 kg ha-1 nitrogen application by preparing the field with chisel plough followed by cultivator.
Key words: Maize productivity, chisel plough, conventional tillage, nitrogen.