| The field experiments were carried out in Yangling and Qishan, which were in the south part of LoessPlateau with about 630mm precipitation each year. Winter wheat cultivars (Xiaoyan22 and Xiaoyan503)were used as indicating crops to study the integrated effect of canopy structure and yield in differentplanting modes (control-C, plastic film mulching for the whole growth period-PFMW, plastic filmmulching for 150 days-PFM150D, three rows planted and one vacant-TRPOV and rainfall catchment-RCM)and different nitrogen fertilizer application (no nitrogen application and nitrogen application 120kgN/hm2).The main results showed as follows: 1. The main results showed as follows on canopy structure: DIFN and LAI were all changed with the wheat's growth from jointing to mature: DIFN wasdecreased at the first and then increased, but LAI was reverse: the least DIFN's 0.437 in anthesis and thelargest was 0.497 in mature; but the largest LAI's 1.73 in anthesis, the least was 1.24 in mature. Thechanges of DIFN and LAI were significantly different at 0.01 in different cultivars. Xiaoyan22's DIFN waslarger then xianyan503, but LAI reverse, and Xiaoyan22's canopy parameters were more sensitive tonitrogen fertilizer. Nitrogen fertilizer increased the LAI and decreased DIFN: LAI increased 102.3%from1.02 to 2.07, DIFN decreased 32.2% from 0.549 to 0.372. The DIFN and LAI of different planting modeswas significantly different at 0.01, the DIFN's sequence from large to small is TRPOV(0.490), (0.479), C(0.479), PFMW (0.436) and PFM150D(0.419), but the LAI's sequence was mainly reverse,PFM150D(1.82), PFMW(1.78), RCM(1.36), TRPOV(1.34), C(1.33). 2. The photosynthetic rate (Pn)of different planting modes were different: the TRPOV and C's Pn werelarger, which were 18.04 μmolCO2m-2.s-1and 18.00μmolCO2m-2.s-1, RCM's was in middle , which was17.11 μmolCO2m-2.s-1, PFMW and PFM150D were smaller, which were 16.45 μmolCO2m-2.s-1 and 16.34μmolCO2m-2.s-1. The population Pn was also different: compared with C(302.76μmolCO2plot-1.s-1),TRPOV(301.85μmolCO2plot-1.s-1) and RCM(282.60μmolCO2plot-1.s-1) individually decreased 0.91μmolCO2plot-1.s-1 and 20.16 μmolCO2plot-1.s-1; PFMW (378.35μmolCO2plot-1.s-1), and PFM150D (371.90μmolCO2plot-1.s-1) were individually increased 75.99μmolCO2plot-1.s-1(25%) and 69.14μmolCO2plot-1.s-1.PFMW and PFM150D's population Pn capacity were higher, which was beneficial to high yield. ThoughRCM's population Pn capacity was lower than C, LAI was higher than C in latter growth period, which wasbeneficial to high yield. 3. During the grain filling period, grain volume was increased quickly in the first stage of grain filling,then increase to the maximum slowly and then decreased quickly. Xiaoyan22's volume was largerXiaoyan503's. In different planting modes, grain volume's sequence was RCM> PFMW>c. The differencewas significantly different at 0.01 in grain filling days, wheat cultivars and in planting modes, but the effectof nitrogen was very little. Water content was decreased nearly lineally. Xiaoyan22's water contentsignificantly higher than Xiaoyan503, but the effect of wheat cultivars and planting modes weren'tsignificantly different. The difference of wheat cultivars'grain dry weight was pertinent to grain fillingprocess. The difference between Xiaoyan22 and Xiaoyan503 wasn't significant in the initial grain fillingperiod, but the difference was increased in the mid and late grain filling period, and Xianyan22's grain dryweight(37.28g per 1000 kernel) was significantly larger than Xiayan(50334.32g per 1000 kernel)in mature.The change of wheat grain's 1000 dry kernel weight showed as "S"in nitrogen and different planting modetreatments. The effect of nitrogen was very little on grain filling characteristic, but the different plantingmodes'influence on different wheat cultivars were different. When it was considered averagely in all grainfilling period, the sequence of Yiaoyan22's grain dry we...
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