Transfer Characteristics Of Assimilation Products And Nutrients For High-yielding And High-efficiency Dryland Spring Maize

Increase of production and resource use efficiency is the new theme of maize cultivation.Maize as one of the important cereal crops in China,its cultivation area and production is in the second place following rice,whereas the yield per unit area of maize ranks first in cereal crops.Although China is the world's second-largest country in maize production,the yields is still at a moderate level compared to developed countries.Therefore,exploration of yield potential and improvement of nitrogen use efficiency of current maize varieties with increasing the amount of fertilizer are main goals of our research.We had built a suitable Plateau of spring maize yield planting system in last four years,theoretical basis of that sufficient or not,which has to be supported by theoretical foundation from cultivation systems and water nitrogen management coupling to climate,in addition to the need to assimilate products from the plant/nutrient accumulation,transfer and source-sink relations.To answer this question,this study presents the basic scientific hypothesis that "compared with the general pattern of farmers planting,yield planting plants in addition to maintaining a strong system of assimilation in the late reproductive capacity,the source department assimilates and nutrients transferred to the sink and to maintain transfer efficiency at a high level." The main purpose of this study was to demonstrate that the reliability of this hypothesis,and to provide a reliable theoretical and practical basis to the constructed reveal Plateau of spring maize yield planting systems.By 2 to 3 years of field testing and laboratory analysis,the following main conclusions were obtained:(1)With the growth stages advance,spring corn N(Nitrogen)uptake increases continuously,during the seedling stage to jointing stage raises slowly while jointing stage to the flowering stage elevate rapidly,and the increase speed slow down again reaching a maximum point in the ripening period.Mulching can significantly increase the spring corn N uptake,which values are 236 kg / hm2 ~ 245 kg / hm2 by mulching and 200 kg / hm2 ~ 217 kg / hm2 by mulching.Compared to the bare and sand covering mulching can increase the N uptake in various organs and especially the promotion and transfer of leaves and stems,whereas the transfer rate and the transfer of nitrogen contribution rate effect are not significant.Mulching did not improve the nitrogen utilization efficiency significantly,however,nitrogen harvest index and nitrogen partial productivity in spring maize increase significantly,and also the yield reached 13334 kg / hm2 ~ 13707 kg / hm2.(2)With the increase of nitrogen supply,spring corn N uptake showing an increasing trend,while the amount of nitrogen supply exceeds 200 kg / hm2 ~ 250 kg / hm2,the plant nitrogen uptake increase was not significant.Nitrogen was 200 kg / hm2 ~ 250 kg / hm2,the plant N uptake was 212 kg / hm2 ~ 264 kg / hm2.Increase the amount of nitrogen can increase leaf,stem + leaf sheath and grain nitrogen accumulation.Nitrogen was 250 kg / hm2,the grain nitrogen accumulation in the ripening period is when 167 kg / hm2 ~ 180 kg / hm2,continue to increase the amount of nitrogen,the effect is not significant.Increase the amount of nitrogen can significantly improve the vegetative organs to grain nitrogen transfer amount,but no significant effect on the vegetative organs transfer of nitrogen on grain nitrogen uptake and nitrogen contribution rate transfer rate.Increase the amount of nitrogen may also increase grain yield.Nitrogen was 250 kg / hm2,the maximum grain yield,is 13.7t / hm2 ~ 15.1t / hm2.Nitrogen use efficiency,nitrogen use efficiency and nitrogen partial physiological productivity rises with the amount of nitrogen decreased significantly.Nitrogen harvest index is not affected by significant amounts of nitrogen.In conclusion,the more appropriate amount of nitrogen was 200 kg / hm2 ~ 250 kg / hm2.(3)With the progress of growth stages,spring corn N uptake increases,an increasing trend for slow increase first,followed by a rapid increase,and then slowly increase the time to reach the maximum ripening period.Removing membrane after flowering growth stage without removing film processing and handling of various organs of spring corn nitrogen accumulation,transfer the amount of nitrogen in different organs and transfer rate,the contribution rate of transfer of nitrogen,nitrogen harvest index,nitrogen utilization,nitrogen physiological efficiency had no significant effect.Removing film after flowering growth stage without removing film processing and handling of spring corn N uptake and grain yield was not significant,but after flowering,removing film treatment increased the spring maize N uptake,was 272 kg / hm2 ~ 320 kg / hm2,increase the grain yield of spring corn,for 15669 kg / hm2 ~ 17523 kg / hm2.In the late spring corn,removing membrane was as effective as mulching.Thus,in the spring maize growth period is not necessary to the whole film,removing membrane effect more pronounced after flowering.Meanwhile,the mulching increases the corn grain volume to expand their storage capacity,thereby increasing grain yield.(5)Removing membrane after flowering through improving leaf area index,ear leaf SPAD value,expand the corn grow,"source",while a single spike by increasing the cob,husk leaves and grain dry weight,single spike grain number and grain volume to expand corn storage capacity.After flowering removing film will promote corn dry weight,dry matter accumulation especially after flowering,increased grain dry matter assimilation,thereby increasing grain yield.And after flowering,removing film had no significant effect on the grain harvest index and grain dry transfer amount.