Effect Of Different Film Mulching Methods On The Grain Filling Of Wheat Under Rainfed Condition

The winter and spring wheat planting mulching, fertilization, sowing date and variety field comparative experiments were carried out in semi-arid rain fed conditions in Loess Plateau and studied the effect of different cultivation factors on grain filling characteristics, yield and agronomic indexes.Five treatments were designed on winter wheat cultivation test, They were Gangu mode(T1),Gansu mode (T2),Shanxi mode (T3), outdoor wheat to drilling(Tc) and outdoor wheat to holing(Tx),The spring wheat was also set up three film-mulching way the same to the winter wheat which based on autumn film and spring film, which was Gangu autumn coated (A1),Gansu autumn film(A2),Shanxi autum film(A3),Gangu spring coated(S1),Gansu spring film (S2),Shanxi spring film (S3), outdoor wheat to the spring drilling(Tc) of seven treatments; Further planting in the new film based on the Gangu mode, set the five spring wheat varieties comparison tests, namely Xihan No 1(C1),Xihan NO.2(C2), Xihan NO.3(C3),Z33(C4) and Z34(C5); The winter wheat fertilization experiment and sowing date experiment were carried out under the open field drilling condition, The fertilization experimental was set totally sixteen treatments, in which pure N and P₂O₅ were located 0,45,75,105 (kg/hm²) four levels; Sowing experiment consists of four sowing dates (day / month) treatments , respectively, 21 / 9 (S1), 30 / 9 (S2), 6 / 10 (S3) and 11/10 (S4).The main results are as follows:1.Grain yield had significantly difference under different cultivation measures of dryland wheat, It was found that cultivation by covering with plastic film showed higher yield potentialities.plastic film mulching respectively increased 25% to 64.4% compared with CK. It was showed that yield of cultivation model T2 was the highest(4312.7kg/hm²), increased 64.4% compared with CK(2623.5kg/hm²); The yield of spring wheat with autumn mulching of Gangu mode(A1) was the highest(2601.3kg/hm²), which increased 62.5% compared with CK(1600.8kg/hm²), the yield of spring wheat of autumn mulching was higher 3.2% than spring mulching.The differernce of grain yield in the variation near one times under plastic mulching(1385.7～2686.1kg/hm²), the yield of Z33(C4) was the lowest, It was 93.8%, 71.5%, 48.7% and 61.8% lower than Z33, respectively. The highest differernce of grain yield in fertilization treatments were 26%(1407.6～1773.4kg/hm²), the grain yield of N₇₅P-(105) was the highest, the best treatment was the N₀P-(75); The highest differernce of grain yield in different sowing times were 25.6%, the optimal sowing times was September thirty. 2.The drying kernel weight had significantly difference among different planting patterns, It was suggested that grain weight had greatly potential to increase through high-yield breeding and cultivation practices. The average drying kernel weight of winter wheat with film mulching comparatively increased by 4.3g compared with CK, The average drying kernel weight of Shanxi mode was the most, and significantly difference with other modes, which was 5g higher than CK; The highest differernce of the average drying kernel weight in fertilization treatments were 2.1g; The highest differernce of the average drying kernel weight in different sowing times were 4.9g.The average drying kernel weight of Gansu mode in spring wheat comparatively increased by 0.6g compared with CK, the average drying kernel weight of Gangu mode comparatively decreased by 4.2g compared with CK, It showed that Gangu mode of spring and autumn mulching would cause decrease of grain weight, Comparison from the mulching time, autumn mulching was beneficial to improve grain weight, the average drying kernel weight of spring wheat with autumn mulching was higher 1.6g than spring mulching. The difference of the average drying kernel weight of the variation of spring wheat under film mulching was 5.1g.3. Under different cultivations, the growth process of the grain weight of winter and spring wheat showed a "slow - fast - slow" of "S"-type trends, The Richards equation curve fitting it well. The time of grain dry matter accumulation in film mulching was short, and accumulation of dry matter was the highest; the time of winter wheat arrived maximal filling rate were about 21ds after anthesis, but delayed the time of arrived maximal filling rate about 3ds,the time of dry matter accumulation can be divided into four periods, the slightly increasing stage was about 3 to 9ds after anthesis, the quickly increasing stage was about 12 to 30ds after anthesis, slowly increasing stage was about 30 to 37/40ds after anthesis, the accumulation dry weight of grain in three periods were 2.8% to 5.4%,54.6% to 73.2%,21.4% to 42.4% of dry weight of mature grains ,respectively; the time of spring wheat arrived maximal filling rate were about 15ds after anthesis, but delayed the time of arrived maximal filling rate about 7ds,the time of dry matter accumulation could be divided into four periods, the slightly increasing stage was about 3 to 9ds after anthesis, the quickly increasing stage was about 15 to 29ds after anthesis, slowly increasing stage was about 33 to 39ds after anthesis, the accumulation dry weight of grain in three periods were 4.5% to 7.3%,58.8% to 72.3%,21.4% to 36.7% of dry weight of mature grains ,respectively.Average grain filling rate, grain filling duration, maximum grain filling rate had significantly difference under different cultivation measures. The average grain filling rate of winter wheat with film mulching comparatively increased by 0.02g/100grain.d compared with CK, grain filling duration was shortened 3ds, maximum grain filling rate increased by 0.06g/100grain.d, the average grain filling rate, maximum grain filling rate among different film mulching were manifested as Shanxi mode>Gangu mode>Gansu mode.4.The average grain filling of spring wheat with autumn and spring mulching comparatively increased by 0.021g/100grain.d and 0.019g/100grain.d compared with CK, the average grain filling of autumn mulching were higher than spring mulching; comparison in film mulching methods, which was manifested as Gangu mode>Shanxi mode. The grain filling duration of autumn and spring mulching were shortened 8ds, autumn mulching was beneficial to prolong the grain filling duration, the grain filling duration, of spring wheat with autumn mulching was longer 1.3ds than spring mulching, Gangu mode was the shortest in different mulching methods, but Gansu mode was the longest.5.In winter wheat film mulching, kernel weight was significant positive correlation with average grain filling rate and maximum grain filling rate, but significant negative correlation with grain filling duration; average grain filling rate was significant negative correlation with grain filling duration and maximum grain filling duration, grain filling duration was significant negative correlation with maximum grain filling rate; In spring film mulching, kernel weight was significant positive correlation with grain filling duration, significant negative correlation with maximum grain filling rate and had no significant correlation with average grain filling rate, average grain filling rate was significant negative correlation with grain filling duration and maximum grain filling duration.6. Film mulching was beneficial to improve transferring of pre-anthesis dry matters, the transferring amount, transferring efficiency and the contribution rate of dry matter of film mulching cultivations were increased by3 9.5%,24.9%,27.9% compared with CK, respectively. Among film mulching methods manifested as Gangu mode was the most, the transferring amount and transferring efficiency and the contribution rate of dry matter showed stem>leaf>sheath in different organics.The tests of different film mulching of spring wheat showed that the transferring amount , transferring efficiency and the contribution rate of dry matter of autumn film mulching were higher than spring film mulching in spring wheat, Gansu mode was the most in the different film mulching, the contribution rate of dry matter of autumn mulching cultivations were increased by16.9% compared with CK, spring mulching cultivations were increased by7.3% compared with CK, Gangu mode was the most in the different film mulching; The transferring amount and the contribution rate of dry matter showed stem was higher than leaves and leaf sheathes.7. During wintering stage, jointing stage, booting stage and anthesis stage, plant water content were measured respectively. The four average plant water contents in winter wheat of fim mulching were higher than CK, anthesis stage was the most one, and wintering stage was the least, the plant water content of film mulching were increased by 9.9% to 205.4% compared with CK from wintering stage to anthesis stage, in different film mulching, the plant water content of Shanxi mode>Gansu mode>Gangu mode from wintering stage to anthesis stage.Cultivation models of spring mulching ,from jointing stage to anthesis, the film mulching plant water content showed a single peak curve, and CK plant was a linear increasing in plant water content, the average plant water content of autumn mulching plants in booting and jointing stage were higher than spring mulching, the plant water content of autumn mulching were increased by 44.2% compared with CK, spring mulching were increased by 14.5% compared with CK, the plant water content of Gansu mode>Gangu mode>Shanxi mode in jointing stage, the plant water content of autumn mulching showed Gangu mode>Gansu mode>Shanxi mode in booting stage and anthesis stage,but spring mulching showed Gansu mode>Gangu mode>Shanxi mode in booting stage,...