Effects Of Organic Fertilizer Application On Yield And Feeding Value Of Forage Sorghum

Forage sorghum(Sorghum bicolor(L.)Moench) has great prospect in development and utilization in agriculture region of south China due to its high yield, high resistance of drought, disease and moisture. It also could be renewable after cutting and be grazed,mowed,silaged and hayed.On the other hand,with the rapid development of intensive cattle husbandry,the large amount of manure was produced and polluted soil,water and air around the intensive cattle farm.Cattle manure fermented as basal fertilizer for planting forage sorghum can not only make full use of livestock waste and reduce environmental pollution,but high quality forage can also be obtained.Effect of organic fertilizer application (Five application rates of organic fertilizer (0,75,150,225 and 300 t-hm-2)were set up, and topdressing was applied with urea at the jointing stage to keep the same nitrogen application amount in all treatments.) on yield and quality of forage sorghum was studied in a field experiment.Effect on the silage quality of forage sorghum was also investigated. The purpose of this study was to provide theoretical basis and technical guidance for planting forage sorghum in Jiangsu province and harmless treatment of manure from intensive cattle farm.The results of study on influence of organic fertilizer application on yield and quality of forage sorghum showed that, the plant height, fresh and dry weight of single plant, the content of acid- detergent fiber and neutral detergent fiber increased under the same nitrogen amount with increasing organic fertilizer application, whereas crude protein and In vitro dry matter digestibility decreased. Both dry matter yield above-ground and digestible dry matter yield increased with increasing organic fertilizer application. The difference of crude protein yield among treatments had no significant change. Using increased urea, the content of crude protein and the growth rate of plant height were significantly improved in less time, but the productivity of dry matter was lowest for the treatment without organic fertilizer.The results of research on effect of organic fertilizer application on silage quality of forage sorghum indicated that, under the same nitrogen application amount, with increasing organic fertilizer application, the fermentation quality of silage decreased after initial increase, the best fermentation quality was obtained at the organic fertilizer rates of 75 t·hm-2 and 150 t·hm-2.Meanwhile,the contents of acid detergent fiber and neutral detergent fiber increased, whereas the content of crude protein and In vitro dry matter digestibility decreased with increasing organic fertilizer application. In order to obtain both good fermentation quality and good feeding value of silage, application of 75-150 t·hm-2 organic fertilizer as the base fertilizer is suitable in forage sorghum growing for silage.All results revealed that, enough organic fertilizer as basal fertilizer should be applied in order to obtain high yield in forage sorghum. Application of 75-150 t·hm-2 organic fertilizer as the basal fertilizer is suitable in forage sorghum growing for silage.