Influence of composted poultry manure and irrigation regimes on some morpho-physiology parameters of maize under semiarid environments

Poultry manure (PM), a rich source for crop nutrients, is produced in ample quantities worldwide. It provides necessary nutrient to soil and has a potential to improve plant water holding availability under semiarid environment. The effect of composted poultry manure (CPM) and irrigation regimes on morpho-physiology of selective maize (Zea mays L.) hybrids (H₁ = drought tolerant, H₂ = drought sensitive) was investigated in this study. Two field experiments were conducted during 2010 and 2011 under randomized complete block design with split split-plot arrangements and three replications of each treatment. Irrigation regimes (I₁ = 300, I₂ = 450, I₃ = 600 mm) were kept in main plots; the two maize hybrids (H₁ and H₂) in sub-plots and nutrient levels (L₁ = recommended rate of NPK (control), L₂ = 8 t ha⁻¹ CPM, L₃ = 10 t ha⁻¹ CPM, and L₄ = 12 t ha⁻¹ CPM) were arranged in sub sub-plots. The drought tolerant hybrid showed best growth under all treatments. Results revealed that maximum leaf area index (LAI) was recorded with the application of the recommended dose of NPK. Low irrigation regimes (I₁ and I₂) highly significantly (P < 0.01) reduced the photosynthesis and transpiration rate in both hybrids while application of 12 t ha⁻¹ CPM was able to partially alleviate the effect of water stress on these parameters. Resultantly, the application of 12 t ha⁻¹ CPM enhanced the plant growth and increased grain yield (21%; 4.17 vs 5.27) under limited water availability (I₂L₄) as compared to the recommended dose of NPK (I₂L₁). However, the nutrient application under control treatment had maximum grain yield. Therefore, shortage of water for maize production might be partially alleviated by the application of 12 t ha⁻¹ CPM.