Soil tillage, irrigation and fertilization effects in cotton crops
A three-year experiment comparing five tillage methods with chemical and green manure fertilizer and two levels of water application of cotton (Gossypium hirsutum. L) are reported in this article. Results showed that conventional tillage had the second best emergence rate and the best flowers and boll numbers and yields. Heavy and rotary cultivators gave similar yields (lower than conventional) although rotary cultivator had the best emergence rate. Disk harrow gave an emergence rate similar to the heavy cultivator but lower yield. Finally no-tillage had the lowest emergence rates and yield. Chemical fertilization gave better yield than green manure but the difference was not significant. Different application rates of irrigation water had negligible effect on yields. An economic analysis of the tillage treatments based on contractor prices, but not considering possible long-term effects on environment and soil fertility showed that farmer margins are best for conventional tillage, followed by the cultivator treatments. The results indicate that green manure can be used instead of chemical fertilizers without considerable income loss for the farmers, but with benefits to the environment and soil. Energy consumption was higher for conventional tillage and rotary cultivator followed by heavy cultivator, disk harrow, and no-tillage.