|
In China, water shortage problem has become increasingly severe. Water shortages ofagricultural water use, especially in northern dry land face more severe challenges. In the caseof limited water resources, how to protect and increase food production become an urgentproblem.The study area was located at the Maize Technology Demonstration Park of ShandongAgricultural University in2009and Agriculture Experimental Station of the ShandongAgricultural University in2010-2011, respectively. The experiment involved3strawmulching treatment, i.e.,1.2,0.6, and0kg/m~2, and2plant type, i.e., compact summer maizeDanyu86and the flat type Chaoshi1. The results were as follows:NTS (no tillage with straw mulch) impacts on soil moisture. In the Tasseling-silkingstage of summer maize, soil moisture content in straw mulching was significantly higher thanthat in non-mulching treatment, the greater the amount of coverage, the higher the moisturecontent of the soil volume. The soil moisture content in80to120cm deep were notdifferences; however, there’re significant difference was found in0to80cm of soil moisturecontent, when the amount of straw mulching was1.2kg/m~2, the soil moisture content wassignificantly higher than the amount of coverage for0.6kg/m~2. when the amount of strawmulch was1.2kg/m~2, the soil moisture content in0to60cm is significantly higher than thosein non-mulching treatments. At maturity stage, in0to60cm deepth, soil moisture content ineach mulching treatments was much lower than those in non-mulching treatments. Soilmoisture content of each treatment tends to be uniform, no significant differences were foundbetween them. Rainfall was uniform, water consumption in mulching treatments wassignificantly higher than those in non-mulching treatments in the later stages of summermaize (from tasseling-silking stage to the harvest). The water consumption in different summer maize plant types had not significant differences. Under NTS,water consumption atsummer maize seeding stage reduced; however, at jointing, tasseling silking stage, andmaturity stage, water consumption increased significantly. The total water consumption hasnot significant difference.NTS impacts on grain yield of different summer maize plant types. The effedt of strawmulching on chlorophyll content in the two summer maize plant types was significant.Chlorophyll content in Danyu86was substantially independent of straw mulching; however,as for Chaoshi1, with the amount of mulching increased, the Chlorophyll content increased inthe amount of7.5%in average, when the coverage is1.2kg/m~2, the increase is particularlyevident. Straw mulching could also increase the leaf area index of summer maize.The moreChlorophyll content, the stronger leaf photosynthesis. NTS reduced the summer maizestomatal conductance, inhibit the invalid evaporation. During the summer maize growingseason in2010, under the condition of straw mulching, the above-ground dry matter inChaoshi1allocation had changed, transferred more to spikes. In2010, the grain yield inDanyu86at the mulching rate of0.6and1.2kg/m~2were1328.8and1204.9g/m~2,respectively, they’re all reached the ultra-high-yield level. The yields of Chaoshi1onmulching had improved. The three-year experiment showed that NTS increased kernels perrow of summer maize. Under the conditions of NTS, different maize types in a reasonableplanting density could be obtained high-yield contrast no straw mulching. Contrast thedifferent maize types, the grain yield in Danyu86was more significant.NTS impacts on the water use efficiency of different plant summer maize. At summermaize tasseling-silking stage, Chaoshi1and Danyu86improve water use efficiency of leaf byNTS. Water use efficiency in NTS had improved to some extent under the premise ofincreased grain yield. Under NTS3-year water use efficiency of summer maize increased by12%on average, and Chaoshi1were more pronounced by NTS.The three years results showed that: To the compact summer maize if the rainfall isexcessive or concentrates in the latter part of the year, the optimal amount of mulching is1.2kg/m~2; if rainfall concentrates in the early year, the optimal amount of mulching is0.6kg/m~2.Under the premise of increasing production, the optimal amount of mulching is1.2kg/m~2to the flat type Chaoshi1.
|