Effects of Planting Densities on the Yields and Forage Nutritive Values of Different Corn(Zea mays L.)Varieties

The forage yields and nutritional quality of silage maize KD 8 and grain-forage maize Shaandan8806 under planting densities of 4.8×10~4,5.85×10~4,6.9×10~4,7.95×10~4 and 9.0×10~4 plants · hm~(-2)were studied.The results showed that the dry matter,grain and forage nutritive yields of silage corn differed from different planting densities.Planting density had significant effects on the nutrient contents of different silage corn types.The crude protein(CP),nitrogen-free extract(NFE) and crude ash(CA) contents of plant decreased with planting density increasing.The ether extract(EE) and crude fiber(CF)contents of plant increased with the density increasing.The CP and EE yields in the seeds of silage maize were significantly lower than that in the seeds of grain-forage maize,whereas the CP and EE yields in the straw of silage maize were significantly higher than that in the straw of grain-forage maize.From the point of view of overall forage nutritive yields,the best planting density of silage corn KD 8 is 8.86×10~4 plants · hm~(-2),and the best planting density of grain-forage maize SD 8806 is 7.77×10~4 plants · hm~(-2).