Assessment of Forage Yield and Quality of Corn (Zea mays) KSC 260 Cultivar under Different Integrate Management of Soil Amendment and Plant Residue

The necessity of using sustainable agricultural systems, especially in agricultural fields, is more important than the development of arable land. Sustainable agriculture is based on the efficient management of the elements of production to improve soil quality and one of the main problems in sustainable agriculture is the lack of organic matter and its consequences. One of the possible, inexpensive and feasible ways to increase organic matter in agricultural lands is to return crop residues to the soil. In sustainable agriculture, the use of compost and vermicompost increases the microbial activity of the soil, which increases the nutrient requirements of the plant, especially the consumed elements, which leads to increased crop yields. In order to evaluate integrated fertilizer management and harvest time on the quality and quantity of corn forage, this experiment was conducted in the research farm of Zabol University in 2016-17 crop year.

An experiment was conducted as factorial based on a randomized complete block design with three replications in the research farm of Zabol University during 2016-17 cropping year. The first factor included 10 fertilization levels: (without fertilization, 30% wheat residue, 60% wheat residues, 90% wheat residues, 30% vermicompost, 60% vermicompost, 100% vermicompost, 10% vermicompost + 90% wheat residues, 40% of vermicompost + 60% of wheat residues and 70% vermicompost + 30% of wheat residues) and the second factor of harvesting time were at two levels: (harvest in milky and dough stages). The studied traits included leaf dry weight, stem dry weight, dry matter digestibility, water-soluble carbon hydrates, crude protein and protein yield, crude fiber, insoluble fiber in acid detergent, insoluble fibers in neutral detergent and ash.

The results of analysis of variance showed that the effect of interaction between harvesting stage and combined fertilizer management systems on leaf dry weight, stem dry weight, dry matter digestibility, the percentage of water-soluble hydrocarbons and insoluble fiber in acid detergent was significant. As the plant mature and the stems grow, the ratio of leaf to stem decreases in forage. The highest leaf dry weight (146 g) and stem dry weight (185.33 g) were obtained in milk militias and in the application of 70% vermicompost and 30% of wheat residues. Mean comparisons showed that the highest digestibility of dry matter (69.72%), the highest percentage of water-soluble carbohydrate (21.17%) was observed in dough stage with the application of 60% of wheat residues. The highest non-soluble fiber in acid detergent (34.85 g / kg dry matter) was obtained in the milky stage of grain and in the application of 70% vermicompost and 30% of the wheat residues. Insoluble fiber in acid detergent was the most important determinant of forage quality. The results of the analysis of variance showed that the effect of harvesting stage on the percentage of crude protein and ash content was very significant; the effect of harvesting stage and the effect of combined fertilizer management systems on the percentage of CF was significant; and the simple effect of combined fertilizer management on the non-soluble fiber (CF) in neutral detergent was meaningful. Comparison of means showed that the highest percentage of crude protein (9.32%) was observed in the milky stage; the highest percentage of crude fiber in the grain dough stage (35.45%) and in the application of 70% vermicompost + 30% wheat residues (36.85%); The most NDF (52.58 g / kg dry matter) in terms of application of 70% vermicompost + 30% of wheat residues; and the highest percentage of Ash (7.21%) in milky stage was obtained. The optimal quality is obtained when the plant has a digestibility of dry matter, crude protein, WSC, and more ash content. In general, using 60% and 100% vermicompost ratios and 60% of wheat residues improved the quality of forage at harvest time from the milky stage. The results of this study confirmed the importance of soil organic matter in improving forage quality.

The results of this study confirmed the importance of soil organic matter in improving forage quality. According to the results of this study, the combined application of vermicompost with wheat residues has improved the quantitative and qualitative traits studied in corn. So that application of 70% vermicompost plus 30% wheat residues increased 2% protein percentage compared to control. Therefore, the application of the combined fertilizer system in the long term increases the content of nitrogen and organic carbon in soil. In general, 70% and 100% vermicompost ratios and 60% of wheat residues improved the quality of forage at harvest time from milking stage. The growth stage at harvest time, the most important determinant of forage quality, is a definite species. Forage quality decreases with the advancement of growth stages