Study On Regulation For Getting Excellent Nutritive Quality And Higher Yield Of Sequential Cropping Corn Silage In The North Of Xinjiang

This paper was studied on yields and forage quality of "nongda 1027"at 5 different densities and 6nitrogen levels, and on yields and forage quality with different harvest date and cutting height. The resultswere as follows:1. With increasing of plant density, leaf area index increased significantly; chlorophyll concentrationin ear leaf and whole plant maize yields increased firstly, then decreased. It was the density of 120 000plant.ha-1 that got the highest chlorophyll concentration and yield at milking stage; and crude protein (CP)concentration of different organs decreased and the concentration of NDF ,ADF,ADL increased; and theactivity of nitric acid reductase in the ear leaf was decreasing. During growing of corn silage, crude protein concentration of whole-plant exhibited a negativerelationship with planting density; the concentration of NDF and ADL exhibited a positive relationship withplanting density. A positive relationship between ADF concentration and planting density was seen at maletetrad stage and milking stage, but had a quadratic response at silking stage and grain filling stage.2. The LAI and dry matter yield of corn silage reached a maximum at an nitrogen rate of 135 kg.ha-1 atjointing stage. Equivalent nitrogen applied one time before planting can decrease the concentration of fiberand lignin. Applying optimum nitrogen at jointing stage could improve crude protein concentration.Nitrogen applied one time can get higher yield and forage quality than applied two time.3. Raising the cutting height will decrease DM yield and protein yield, but increase forage quality.4. With harvest date, DM yield increased,forage moisture and CP concentration decreased, theconcentration of NDF and ADF exhibited a quadratic response, ADL concentration had not changedsignificantly. Lower planting densities(less than 120 000 plant.ha-1) had lower moisture but higher DMyields. Higher planting densities(more than　120 000 plant.ha-1) had higher moisture, DM yields increasedsignificantly at the former stage, and increased slightly at the later stage.