| The effects of different micro-field rainwater-harvesting patterns on the regulation of maize growth and development dynamics,biomass yield and WUE were studied before,but their physiological and ecological mechanism was less studied.The aim of this paper is to explain the key scientific problems of soil water convergence effect,changes of soil temperature,soil quality and eco-stoichiometric characteristics of soil-maize leaves,and supplement the pot experiment with different water treatments.The field maize variety "Jinkai 3" was used,and field and pot experiments were carried out in Yuzhong Campus of Lanzhou University in 2015 and 2016.The field experiment had different micro-field rain-harvesting mode(whole plastic-film mulching on alternative furrows and planting in ridges as RF,flat planting with whole film as FF,whole plastic-film mulching on double ridges and planting in catchment furrows as DF,flat planting with no film as CK),pot experiment for different water treatments and fertilizer treatments.the soil water content,soil temperature and soil nutrient,maize growth pattern,eco-stoichiometric characteristics,leaf nutrient elements,yield and water use efficiency were analyzed.Main conclusions were as follows:A)Study on maize yield formation and eco-stoichiometric characteristics of micro-field rain-harvesting system.1.The micro-environment was greatly improved in micro-field rainwater-harvesting system,and the stem diameter,stem height,leaf area index,leaf area index,stem weight,leaf weight and spike biomass distribution of maize,yield and water use efficiency were significantly higher than no furrow-ridge mulching control.For two years on average,DF showed a maximum plant height was 217.81 cm,which was 60.5% higher than CK,LAI was 3.28,which was 66.7% higher than that of CK,above-ground biomass is 255.92g/plant,which was 227.0% higher than CK in flowering period,followed by RF,FF was the lowest.For the two-year average,theyield,water use efficiency for yield,harvest index and WUE for shoot biomass of DF were the highest,which were 131.6%,122.1%,33.2%,62.7% higher than CK respectively.2.In the micro-field rainwater-harvesting system,the soil water storage within 1m was significantly higher than that without mulching at seedling stage.Compared with CK 0-20 cm SWS,the RF,FF and DF increased by 63.3%,40.5% and 65.4%,respectively in 2015;compared with that of CK,these increased by 9.7%,19.8% and24.1% respectively in 2016.Compared with CK 20-60 cm SWS,the RF,FF and DF of increased by 3.8%,10.2% and 1.6% respectively;and 25.3%,22.0% and 15.3%respectively in 2016.In addition,mulching can significantly improve the soil temperature throughout the growing season(about 3.53℃~5.03℃),which is undoubtedly provides favorable conditions in crop emergence and seedling process.3.During the whole growth period,the soil organic carbon content,the C/N ratio and the C/P ratio showed a decreasing trend,soil total phosphorus content showed a rising trend;leaf organic carbon,leaf phosphorus,total nitrogen content showed a downward trend,while the leaf C/N ratio,leaf C/P ratio,leaf N/P ratio showed an increasing trend.The contents of soil organic carbon,soil total nitrogen and total phosphorus were significantly decreased,and soil C/N and C/P ratio also showed a decreasing trend,but the N/P ratio increased.The leaf organic carbon and the total nitrogen content decreased,the C/N ratio and the C/P ratio were also reduced.Nitrogen addition increases the total nitrogen content of the leaves.Plant growth is limited by nitrogen or phosphorus.B)Study on maize yield formation and eco-stoichiometric characteristics under potted water control4.The leaf area of N3 was the highest as 6986.09cm2/plant,which was 634%higher than CK(N0))under sufficient water supply,and the photosynthetic rate was the highest(99.09% higher than CK)under sufficient water supply.The above-ground biomass was the highest(1020.34% higher than CK),but under moderate drought condition,the photosynthesis of N1 or N2 was the strongest,and the biomass of N2 was the highest(1162.65% higher than CK).Under water stress,maize growth was greatly restricted,and the yield and WUE of maize were decreased after exceeding the optimum nitrogen application.On the whole,the yield of different nitrogen treatments decreased due to drought stress,but with the increase of nitrogen application,the yield decreased greatly.5.The contents of organic carbon,the C/N and C/P and N/P ratios in leavesdecreased with the increase of total phosphorus content,and the contents of soil organic carbon,C/N and C/P were higher than those in the whole growth period.Leaf total nitrogen and total phosphorus contents showed a decreasing trend.The content of soil organic carbon,the C/P ratio,the content of total nitrogen,the N/P ratio increased;the leaf total nitrogen content increased,the C/N and C/P ratio decreased,and the N/P ratio rise.With the increase of water supply,soil organic carbon,total phosphorus content,the ratio of C/N,the ratio of C/P increased,soil nitrogen content,the ratio of N/P decreased;leaf organic carbon,total nitrogen,total phosphorus contents has a decreasing trend,The C/N and C/P and N/P ratios of the leaves showed an increasing trend.In the pot experiment,maize growth was limited by nitrogen. |
PDF Full Text Request