Effects Of Different Planting Densities On Material Production And NPK Absorption Utilization Of Spring Maize

Increasing the planting density is one of the main ways to increase yield, the increase of planting density is bound to have a certain influence on spring maize yield, dry matter, nutrient accumulation and transportation. This research was studied in the experimental farm of Inner Mongolia university for nationalities in 2013 and 2014,with the main materials in the West Liaohe plain about Zhengdan958 and Weike702, under five planting densities, 45 000(D1), 60 000(D2), 75 000(D3), 90 000(D4), 105 000(D5) plants/hm2. The responses of different planting densities on agronomic characteristics, accumulation and transportation of dry matter and nutrient about spring maize were studied through the two years’ field test. The results showed that:The yield of two varieties increased first and decreased afterwards with the planting density increased and reached the highest yield under the D4 density. Zhengdan958 had the highest yield of 13.945t/hm2(2013) and 13.981t/hm2(2014), compared with the density of D1, respectively increased by 10.11%(2013) and 13.21%(2014); Weike702 had the highest yield of 16.088t/hm2(2013) and 14.606t/hm2(2014), compared with the density of D1, respectively increased by 20.07%(2013)and 34.87%(2014).With the planting density increasing, grain number and 1000-grain weight both decreased.With the planting density increasing, plant height and ear height both increased first and decreased afterwards, the maximum height occurred at D4 of two varieties, ear longth increased and stem diameter decreased.With the planting density increasing, two varieties of dry matter accumulation amounts increased before silking, and after silking increased first and decreased afterwards; accumulation rate increased before silking and decreased after silking in the overall performance; the contribution rate to grain fall after raise with the planting density increased before silking, and increased with the increasing planting density after silking. With the increase of planting density, leaf, stem-sheath translocation amount, meantime, stem-sheath translocation rate increased, leaf translocation rate decreased; the contribution rate of leaves, stem-sheath translocation to grain reached the highest under the D4 density. With the planting density increasing, leaves and spikes distribution rate decreased, stem and sheath distribution rate increased in the overall performance, the grain distribution ratio fall after raise in mature stage.With the increase of planting density, the N content of stem-sheath increased first and decreased afterwards in silking stage, P content increased and K content increased; The N and K contents of leaf increased, P content decreased; N, P and K contents all increased. N, P and K contents of each organ all decreased in mature stage, P and K contents differences of leaf were not significant. N, P and K accumulations of each organ about two varieties in silking and mature stage were all increased in the overall performance.The accumulation rates of N, P and K increased before silking about the whole plant, after mature stage the rate was declined in the overall performance. To the different organs, the translocation amount and translocation rate of N in stem-sheath and leaf were increased, the contribution rate about the translocation amount of N in stem-sheath to the yield, Zhengdan 958 had the highest rate under D4(2013) and D5(2014) density, Weike702 both had the highest rate under the D5 density; translocation rate of P in stem-sheath increased first and decreased afterwards in general, translocation rate of P in leaf had no obvious regularity; the translocation amount and translocation rate, the contribution rate of K in stem-sheath and leaf were increased in the overall performance.