| Rapeseed is one of the main oil crops in the world. Recently, people paid much attentionto rapeseed as a agricultural landscape crop. The history of rapeseed planting in Australia isshort, but the rapeseed industry has developed very quickly. The planting area has reached3millions hectare in2012. Researching focusing on the rapeseed field had developed very fastin Australia. China has ranked to the top in the world concerning rapeseed planting area. TheYangtze River basin in China is the main production areas for winter rapeseed. The north ofChina is the main production region of spring rapeseed. With climate changing and evolutionof cultivation measures, the relevant research for rapeseed growth and yield change alsoincreasingly followed up. However, the agricultural production system is a dynamic systemwhich was influenced by many other factors, such as weather, soil, variety and cultivationmanagement. It is very difficult for the agricultural producers to comprehensively conside thefactors interaction, forecast the trend of agricultural production and quantify the factors on theinfluence of crop production. Crop growth simulation model provides a new method, which isa quantitative description of the crop growth and development process and the interactiverelations between the environment and cultivation technology. We had studied the effect ofIndia mustard and Australian hybrid rapeseed with different temperature and irrigationconditions under elevated CO2. And the experiment of dual-purpose agriculture wasconducted at Young and Wagga wagga of New South Wales in Australia. By the rapeseedgrowth simulation model (APSIM-rapeseed) and GIS, we analyzed the trend of climateelements during rapeseed growth period from1951to2009, and discussed the managementaction and future climate change effect on rapeseed growth and yield in China. The results ofstudy as follows:1) The APSIM-canola model was calibrated and tested using data from fieldexperimental sites in China. These experiments included different cultivars, sowing dates, andrecorded major growth stages, biomass and grain yield. After calibration of phenologicalparameters and maximum harvest index, the model was able to simulate onset of phenological stages with different sowing dates, and to explain the variation in biomass and yield. TheRMSE between simulated and observed data of phenology, biomass and yield on winterrapeseed were1.67d,783.5kg.ha-1and520.3kg.ha-1, respectively. And the R2were0.98,0.71and0.70, respectively. Meanwhile, the RMSE between simulated and observed data ofvegetative growing period, whole growing period and yield on spring rapeseed were3.05d,2.29d and318.61kg.ha-1, respectively. And the R2were0.91,0.98and0.85, respectively. Theperformance of APSIM-canola model has been tested and applied well in China. The workpresents the first step in further use of APSIM to study effect of climatic variation andmanagement practice on rapeseed yield potential in China.2)The combined effect of elevated CO2, high temperature and terminal drought onbiomass accumulation and grain yield was evaluated in Brassica juncea JL1and Brassicanapus Hyola42rapeseed genotypes grown under elevated CO2(700μmol.mol1) combinedwith temperatures2℃,4℃and6℃above the current ambient temperature. Terminaldrought was induced in all combinations at anthesis in a split-plot design to test whether theeffect of elevated CO2combined with high temperature ameliorates the negative effects ofterminal drought on biomass accumulation and grain yield. Biomass and grain yield wereenhanced under elevated CO2with2℃above the ambient temperature, regardless of thewatering regimen. The combinations of elevated CO2plus4℃or6℃above the ambienttemperature did not enhance biomass and grain yield, but tended to decrease them. Thereductions in biomass and grain yield caused by terminal drought were more significant. Thecombinations of situation resulted from a decrease in the rate of leaf net photosynthesis in JL1and Hoyla42. The transpiration rate of leaf is changed similarly as the rate of leaf netphotosynthesis. The changes of above ground biomass are not significant with irrigationscheme. The contrasting responses and phenological development of these two genotypes tothe combination of elevated CO2, temperature and terminal drought are discussed. Accordingthe trend analysis of climate change, we used APSIM-rapeseed simulated rapeseedproduction which under different levels of CO2. Based on the analysis of model simulationresults, we found that: The growth length of rapeseed was shortened by elevated CO2concentration. When the concentration of CO2double increased which caused rapeseedpotential yield and rain-fed yield increased. The increased yield at Shimen site was significantunder A1B gas emission scenario; When the concentration of CO2elevated to700μmol.mol1and the ambient temperature increased by2℃, the potential yield and rain-fedyield be increased by the elevated CO2in all sites. But the potential yield and rain-fed yieldwas decreased when the ambient temperature increased by4℃and6℃. In some extent, thatshowed the elevated CO2concentration has declined yields which due to lack rainfall. 3) Without considering the fertilization effects of CO2, we studied on China rapeseedplanting regionalization, planting area, yield and measured data in China. Three typical winterrapeseed planting site (Wuhan, Nanjing, Shimen) be selected as the research objects in themain winter rapeseed production areas-Yangtze River Basin. The change of climate elementswith time trend during rapeseed growth period is analyzed. Using the rapeseed growthsimulation model APSIM-rapeseed quantify the influence by climate change on rapeseedgrowth and yield. The influence of rapeseed growth period and yield by long-term climatechange is quantified by using statistical approaches. The results show that: this study foundthat late sowing rapeseed yield decreased has a negative correlation with winter temperature,and the vegetative stage and the flowering period is shortened ultimately which are led to theyield decrease directly. Based on the analysis the influence of long-term climate change on therapeseed growth and development, we found that the length of the vegetative stage has adirect impact to rapeseed production. Therefore, we can try to use early sowing to extendrapeseed growth development period in Wuhan area, so as to achieve the purpose of increaseproduction.4) The dual-purpose agriculture experiment of rapeseed was conducted at young andwagga wagga, New South Wales state, Australia. The result found that the effect ofdual-purpose agriculture was not similar when under different climate conditions. The climatefactors of experimental sites in Australia and simulated sites in China are analyzed. Therewere plenty rainfall, low difference of max temperature and min temperature and short wintertime at Shimen site when rapeseed had restored form grazing. Although Australia sites hadlonger sunshine hour than Shimen site, but the long winter time with low temperature andrainfall shortness is a weakness point for rapeseed regrown. Especially at Wagga wagga sitewhich under rain-fed zone. So it got lower yield and harvest index at Australia sites. In theprocess of simulation for dual-purpose agriculture in Shimen by used APSIM-grazing, wefound that the farmer got money about21765yuan/ha from dual-purpose agriculture, which is9285yuan/ha more than traditional agriculture. Therefore, Chinese winter rapeseed attempt toimplement dual-purpose agricultural in the Shimen area is feasible.5) Based on the APSIM parameters were comprehensively sensitivity analysis andcalibration, we analyzed the yield fluctuation with no irrigation cases in three sites whichunder different annual precipitation type and different nitrogen application rates. Yield hadvaried sharply with the rainfall fluctuations in different years when nitrogen application iszero. The coefficient of variation of three areas became stable gradually when nitrogenfertilizer is applied. The influence of rainfall yield was not significant when nitrogen rates beapplied with50kg/ha and150kg/ha and200kg/ha in Nanjing, Wuhan and Shimen, respectively. The optimum policy which is gives consideration both for yield and the cost ofnitrogen application and irrigation from nine scenarios. The result is we can achieve theoptimal economic benefit when the irrigation efficiency achieved30%and nitrogen appliedrate for270kg/ha.6) The climate data from1961s to2010s in spring rapeseed production regions wereanalyzed by GIS technology. During the whole rapeseed growing period, the averagemaximum, minimum temperature and the temperature difference in2000s in the springproduction region were higher than that in1980s, while the total precipitation and sunshinehours were varied in different place. The frequency of serious low temperature and colddamage was lower and lower, while the dry index was became higher and higher. Researcherswill pay more attentions to how to improve the resistant drought of rapeseed.Compared with1980s, the yield in2000s decreased by19.5%. Negative correlation was found betweenmaximum temperature and simulated rapeseed yield. However, minimum temperature waspositively related to the detrended rapeseed yield in most regions. The relationship betweendetrended simulated rapeseed yield and solar radiation was negative. The relationshipbetween detrended simulated rapeseed yield and total precipitation were inconclusivethroughout north regions of China in terms of statistically significant spatial patterns.Cultivars updating will as a main method to against the future climatic changes. |
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