| Corn is one of three major grain crops in the world, which also occupies a very important position in China. At present, China is suffering from a severe water shortage. It is of great significance to alleviate the shortage of water resources and increase corn yield when fully utilize precipitation and improve water use efficiency of corn under the non-irrigated condition. The experiment was conducted in the Northwest Agriculture and Forestry University experimental site located in southern Ningxia Guyuan semi-arid mountains in 2014. The experiment selects corn Zhengdan958 which has compact plant type and suitable for close planting. This research set three density treatments(D), 45000 plants/hm2(D1), 60000 plants/hm2(D2),75000 plants/hm2(D3),respectively, and Four nitrogen and phosphorus fertilizer combination treatments(NP), 0 kg/hm2 for N,0 kg/hm2 for P(CK), 150 kg/hm2 for N, 60 kg/hm2 for P(N1P1),300 kg/hm2 for N,120 kg/hm2 for P(N2P2), 450 kg/hm2 for N, 180 kg/hm2 for P(N3P3). Through field experiment to study the growth conditions of corn, water use efficiency and yield under different densities and different nitrogen and phosphorus fertilizer applications respectively. The results as follows:1. The yield of corn has different variations with the increasing of planting densities and N,P fertilizer applications. The yield of corn increased with planting density increasing. The highest planting density 75000 plants/hm2 has the maximum yield 12289.24 kg/hm2. With the increase of nitrogen and phosphorus application the corn production increased then decreased, the order of yield is N2P2> N3 P 3> N1P1> CK. the highest yield is 11871.56 kg / hm2, therefore N 300 kg / hm2, P 120 kg / hm2, is the best nitrogen and phosphorus fertilizer applications for corn.2. With the increasing of planting density of corn,the plant biomass decreased,but total biomass is increased, the plant biomass reached a minimum 122.24 kg/plant with density of 75000 plants/hm2,total biomass reached maximum 21272.19 kg/hm2 with density of 60000 plants/hm2.With the increasing of amount of nitrogen and phosphorus fertilizer applied the biomass of plant and total were increased firstly then reduced. In the N 300 kg/hm2, P 120 kg/hm2 reached maximum plant biomass which was 145.61 kg/plant and total biomass which was 21712.49 kg/hm2.3. With the increasing of planting density, ear length, spike grain number and grain weight 100-seeds grain weight were reduced, the maximum values of these characteristic got at 45000 plants/hm2. With the increasing of nitrogen and phosphorus applied, ear length, ear of corn grain number, spike grain weight, 100-seeds grain weight were first increased and then decreased, when fertilizer with 300 kg/hm2 for N, 120 kg/hm2 for P corn yield reached the maximum value, 19.97 cm for ear length, 594.67 grains/ear for ear of corn grain, 145 kg/ear for grain number per ear, 24.22 kg for 100-seeds grain weight..4. With the increasing of density the grain water use efficiency first increased and then decreased, When the planting density is 60000 plants/hm2 the WUE reached maximum value 20.34 kg/(hm2·mm).the changing trend of water use efficiency of biomass is consistent with the grain water use efficiency. It reached the maximum value 37.20 kg/(hm2·mm) in planting density was 60000 plants/ hm2.With the increasing of nitrogen and phosphorus applications the grain water use efficiency first increased and then decreased. It reached the value when the fertilizer rate was 300 kg/hm2 for N, 120 kg/hm2 for P. Biomass Water Use efficiency has a similar trends with grain water use efficiency. It reached the maximum value 37.20 kg/(hm2·mm)in fertilizer rate 300 kg/hm2 for N,120 kg/hm2 for P.5. With the increasing of nitrogen and phosphorus fertilizer applied, the net benefits of corn first increased and then decreased. Comprehensive analysis indicated that it can the obtain higher economic benefits with planting density of 60000 plants/hm2,nitrogen and phosphate application of 300 kg/hm2 for N,120 kg/hm2 for P.The results of the experiment indicated that the film-covered corn can attained high yield with planting density 60000 plants/hm2 and fertilizer application 300 kg/hm2 for N,120kg/hm2 for P under the high flow year in the mountainous areas of Ningxia. |
PDF Full Text Request