| ABSTRACT:In order to explore the optimization cultivation management model and achieve the high target yield and efficiency in winter wheat, four cultivation management modes including the current pattern which was traditionally used by farmers(FM), the adjustment pattern1(AM1), the adjustment pattern2(AM2) and the adjustment pattern3(AM3) were conducted with the particular wheat variety(Ping An8)at Wen County in Henan Province during2009-2011. With the application of nonlinear Richards growth model to simulate dry matter accumulation and nitrogen accumulation to research regulation of dry matter accumulation and nitrogen accumulation, with nitrogen balance principle to evaluation the nitrogen surplus situation of different cultivation management mode and analysis the whereabouts of the source of nitrogen in the cultivation system, and with application of systems engineering approach to analyze and evaluate the overall efficiency of the cultivation and management mode, with those indicators to explore efficient optimization of winter wheat cultivation and management mode. The main results were as follows:1. Effect of different cultivation management models on dry matter form a dynamic of winter wheatThe experiment result showed that the dry matter accumulation were significant differences among the various models in mature. The highest dry matter accumulation was AM2model, and the lowest was FM model, and AM2was increased by12.94%than FM model. With the model of dry matter accumulation, the results showed that comparing with FM model, the number of growth period days reduced4d. The whole growth period can be divided into early, middle, and late three stages; the days of early stage of FM less than AM, and there were little difference between middle and late stage. The total days of middle and late stage are54d, which accounted for22.67%of the winter wheat growth period, but the dry matter accumulation of the two periods contributed about53.64%. Different mode of cultivation and management of dry matter accumulation rate had significant differences. The time of maximum rate, maximum rate and average rate of FM, AM1, AM2, AM3were199d,203d,202d,202d and279.68kg/d/hm2,328.02kg/d/hm2,380.38kg/d/hm2,339.67kg/d/hm2and171.44kg/d/hm2,203.58kg/d/hm2,236.61 kg/d/hm2,210.07kg/d/hm2. From the entire growth periods, relative to the AM mode, dry matter accumulation characterized of FM mode was higher rate of early stage and early to reach the maximum rate,but had the lower maximum rate and the average rate.2. Effect of different cultivation management models on yield formation of winter wheat and nitrogen use efficiencyCompared with FM mode, AM1, AM2and AM3mode yield of2009-2010and2010-2011were increased by3.25%,12.78%,7.60%and4.11%,13.10%,7.95%. From the yield component analysis, there were more spikes in FM than others, but the grain number per spike and the grain weight were significantly lower than other models so that the yield was significantly lower than adjustment models. There was significant difference between different modes of harvest index, biomass and harvest index showed AM1improved, but not obvious synergistic increase; AM2compared with AM3, AM2biomass was significantly higher than that of AM3, while the economic coefficient of AM2does not significantly reduce resulted in no significant difference in grain yield between two production systems. Therefore, we can increase the yield and harvest index by increasing grain number per spike and grain weight in proper cultivation management models.The nitrogen absolutely absorbed performance showed as AM2>AM3>AM1>FM, compared with FM, AM model of grain nitrogen uptake increased by7.66%,23.67%and17.18%.From the utilization rate of nitrogen fertilizer, nitrogen agronomic efficiency difference of different management mode were significant, AM3was the highest. AM2compared with AM3, under the condition of no significant difference in dry matter production, AM3through the reduction of nitrogen fertilizer management measures to improve the agronomic N use efficiency; Nitrogen partial productivity2years results showed AM1>AM3>FM>AM2, and that showed AM1has higher nitrogen economic efficiency. These results suggest that the appropriate reduction in the amount of nitrogen fertilizer can not only improve the amount of nitrogen uptake, but also improve nitrogen use efficiency.3. Effect of different cultivation management models on Shoot nitrogen accumulation and soil nitrogen supplyThe experiment result showed that the nitrogen accumulation were significant differences among the various models in mature. The highest dry matter accumulation was AM2model, and the lowest was FM model, and AM2was increased by19.05%than FM model. With the model of nitrogen accumulation, the results showed that its very similar to the days of growth period of dry matter accumulation and nitrogen accumulation. The nitrogen accumulation difference among different cultivation management models mainly due to nitrogen accumulation rate. The time of maximum rate, maximum rate and average rate of FM, AM1, AM2, AM3were185d,200d,196d,197d and2.31kg/d/hm2,2.68kg/d/hm2,3.59kg/d/hm2,3.54kg/d/hm2and1.43kg/d/hm2,1.64kg/d/hm2,2.19kg/d/hm2,2.17kg/d/hm2.With the jointing stage application of nitrogen fertilizer in AM cultivation management models, the characterized of soil inorganic nitrogen supply was by a sharp rise from sowing to the wintering, from the wintering stage to jointing of rapid decline, slow decline from jointing stage to maturity. Because FM cultivation management mode all the nitrogen fertilizer application at sowing, soil inorganic nitrogen supply declined continuously. The jointing stage AM2models of soil nitrogen supply compared to AMI, FM were increased by54%,27%, AM1inorganic nitrogen supply had low because of the early nitrogen application rate minimum, but the nitrogen fertilizer application at jointing stage eased the demand for nitrogen in the later period of Wheat. The low content of soil inorganic nitrogen in FM cultivation management mode had limited later period of wheat growth.4. Effect of different cultivation management models on Nitrogen balance of winter wheatThe whole growth period of nitrogen surplus showed as:AM2>FM>AM3>AM1, and the difference was significant. Compared with AM2mode and FM mode, there had no significant difference from2010to2011. Nitrogen surplus comes mainly from the nitrogen residual in soil, because nitrogenous fertilizer of FM mode were applied totally as basal application, nitrogen concentration had high in early stage of soil and soil nitrogen concentration had low at later growth stage, FM mode had less soil residual nitrogen and high apparent loss. In the nitrogen input, nitrogenous fertilizer hit40%-53%of total input, and sum of mineralization of soil and the initial inorganic nitrogen hit42%-53%. In the output, Wheat nitrogen uptake accounted for an average of62%of total output. In all, through the nitrogen management and improve wheat uptake nitrogen is the main measures to control the nitrogen surplus.Form Sowing to jointing stage, nitrogen was the main crop nitrogen input pathway, the main output pathway was soil inorganic N residue, followed by crop uptake of nitrogen, and FM apparent nitrogen loss was significantly higher than that of AM, nitrogen supply excessive in early stage increase N apparent loss. From jointing to maturity was wheat material fast accumulation period, and need a large amount of nitrogen supply in that time. From the stage of entry, a period of soil inorganic N residue (ratio of48%-72%) was the main input, and the second was nitrogen fertilizer application amount. The main output pathway was crop uptake of nitrogen, and followed by soil inorganic N residue, and without nitrogen fertilizer supplement of FM mode, FM mode had shortage nitrogen supplement when compared with other management modes at late growth stage. The period AM2total N was the highest, but the total amount of nitrogen application (base+topdressing) may be the cause of high crop nitrogen surplus of high.5. Comprehensive benefit evaluation on different cultivation management models of winter wheatThe results showed that the Overall efficiency showed an increasing trend of AM3> AM2AM1> FM, the comprehensive benefits of AM3was higher than that of FM by16.50%. From the economic benefits, AM3was the highest in the experiment of two years, followed by AMI, and the AM2was the lowest. The benefits from the lower fertilizer inputs of AM2was higher than the benefits from the lower output, which was the reason why AM3was higher than FM by9.00%and AM2was lower than AM3; the proportion of the direct production costs in the total cost were59.33%,46.08%,58.98%,52.79%respectively, and the average proportion (54.30%) was exceeding50%, in the direct production costs, fertilizer and seed occupy the largest proportion, accounting for70%-80%. Conclusion:The total output value presents an ascending trend, but the input-output ratio and material input net production rate showed the "N" fonts law of elevated-reduce-re-elevated; the comprehensive benefits of the cultivation and management model of AM3showed highest to balance the contradiction between the economic benefits, social benefits and the ecological benefits, which made AM3have the value of the application and popularization.Comprehensive comparison the effects of different cultivation management models on wheat growth and development, fertilizer and water environment, grain yield formation, carbon and nitrogen metabolism, dry matter production and nitrogen use efficiency, AM1is a cultivated management model which should be popularized in current wheat production, but with the development of wheat production, the improvement of yield and the efficient use of resources requirements, AM3will have a great development.Comprehensive comparison of different cultivation management modes on winter wheat dry matter production, yield component, synchronization of the nitrogen accumulation and soil nitrogen supply, nitrogen balance, and the comprehensive benefit evaluation, AMI is a cultivated management model which should be popularized in current wheat production, but with the development of wheat production, the improvement of yield and the efficient use of resources requirements, AM3will have a great development. |
PDF Full Text Request