Response of Wheat to Vermicompost and Chemical Fertilizers Residual in Soil

Efficient use and management of organic matter are important aspects of sustainable agricultural. Organic matter is relatively low in majority of soils in Iran, and continuous use of chemical fertilizer would create environmental hazards. Therefore, the combined use of chemical fertilizer and organic matter is an effective strategy. In order to study the effect of vermicompost and chemical fertilizer residual on yield, yield component and quality of wheat (Triticum aestivum L.), a field experiment based on randomized complete block design (with 11 treatment and 4 replications) was conducted in Kermanshah Agricultural Research center during 2014. Treatments included: 1- application of 50% of NPK fertilizers, 2- 50% NPK+ 3 ton of vermicompost, 3- 50% NPK+ 5 ton of vermicompost, 4- 50% NPK+ 7 ton of vermicompost, 5- 100% NPK, 6- 3 ton vermicompost, 7- 5 ton vermicompost, 8- 7 ton vermicompost, 9- 3 ton vermicompost+ (100% NPK- equivalent amount of nutrients in 3 ton vermicompost), 10- 5 ton vermicompost+ (100% NPK- equivalent amount of nutrients in 5 ton vermicompost), 11- 7 ton vermicompost+ (100% NPK- equivalent amount of nutrients in 7 ton vermicompost). Results showed the highest and lowest seed number per spike were observed after the application of 11, 4 and 1, 6 treatments, respectively. The greatest 1000-seed weight was achieved by application of 11 treatment that increased 15.88 and 6.31 percent in comparison with 50% and 100% of NPK treatments, respectively. Also, the greatest biological and grain yield were observed in 11 treatment. The highest (998.6 kg.ha-1) and lowest (403.4 kg.ha-1) protein yield were belonged to 11 and 6 treatments, respectively. Grain P, Fe, Zn and Mn concentration were improved by integrated application of vermicompost and chemical fertilizer. On the basis of results, the integrated nutrition 7 ton vermicompost with 100% NPK minus equivalent amount of nutrients in 7 ton vermicompost residual improved wheat quantity and quality properties in comparison other treatments.