| Dryland agriculture occupies an extremely important sector in Chinese agriculture. Mulching and tillage have gained some effect to solve the problem of water scarcity. Order to study the relationship between water and yield and N absorption and assimilation, field experiments was carried out to study the effect of nitrogen and phosphate fertilizer and its application time, the main results are as follows(1) The tillage mothed of subsoiling in fallow period can improve soil moisture conditions at sowing stage of dryland wheat. Compared to no-tillage in fallow period, subsoiling in fallow period the increasing amount of water storage increased 23.07 mm, water storage efficiency in fallow period improved 8.13%. Tillage in fallow period can increase water storage of the 0-300 cm at winter stage, turn-greening stage, booting stage and mature stage. Tillage in fallow period increased winter stage soil water at depth of the 120-200 cm,260 cm and 300 cm, increase elongation stage soil water at depth of 40 cm and 140-280 cm, increase booting stage soil water at all depth expect 20 cm,60-80 cm,160 cm, increase anthesis stage soil water at depth of 20-40 cm,140-160 cm,200 cm and 240-260 cm, increase mature stage soil water at all depth expect 80-120 cm. Tillage in fallow period can increase grain protein and its component contents, protein yield, ear number,1000-grainweight,yield and WUE(water use efficiency), and subsoiling in fallow period had better effect. Compared to no-tillage in fallow period, subsoiling in fallow period the ear number increased 218.3 thousand per hectare, yield increased 153.14 kg·hm-2 and protein yield increased 36.39 kg·hm-2.(2)Under the condition of subsoiling and phosphorus fertilizer applicated in fallow period, when the phosphorus application amount increased from 90 kg·hm-2 to 270 kg·hm-2, the water storage of the 0-300 cm at winter stage and anthesis stages was increased, the water storage of the 0-300 cm at turn-greening stage, elongation stage, booting stage and mature stage was increased significantly, the content of nitrate-nitrogen at the depth of 20-100 cm,140-180 cm and 240-300 cm at mature stage was decreased. Phosphorus fertilizer applicated in fallow period, the plant height at winter stage, turn-greening stage and mature stage, the leaf area at different growth stage expect anthesis stages and the dry biomass at different growth stage were the highest when phosphorus application was 180 kg·hm-2. When increased the phosphorus application amount from 90 kg·hm-2 to 270 kg·hm-2,the spike length firstly increased and then decreased, the bearing spikelet number increased, the sterility spikelet number firstly decreased and then increased, the nitrogen accumulation amount of leaf, glume and spike stem at mature stage firstly decreased and then increased, the nitrogen accumulation amount of stem and sheath, grain, overground part at mature stage, the remobilization of pre-anthesis stored nitrogen of different organs, NABA and NAAA firstly decreased and then increased. When phosphorus application was 180 kg·hm-2 the wheat gained the significantly highest ear number, yield, NUE(N uptake efficiency),NPFP(N partial factor productivity) and NHI(N harvest index). The grain protein and its component contents, Glu/Gli and the protein yield was also the highest when phosphorus application was 180 kg·hm-2.(3) Compared to phosphorus fertilizer applicated before sowing, phosphorus fertilizer applicated in fallow period can increase the plant height at different growth stage expect booting stage, the leaf area and the dry biomass at different growth stage, increase the remobilization amount of pre-anthesis stored nitrogen of different organs, the remobilization rate of pre-anthesis stored nitrogen of stem and sheath, Glume and spike stem, vegetative organ, significantly increase the nitrogen accumulation amount of leaf, grain and overground part at mature stage, NABA, NUE, NPFP, NHI, ear number and yield. When phosphorus application was 180 kg·hm-2, compared to phosphorus fertilizer applicated before sowing, phosphorus fertilizer applicated in fallow period can significantly increase the water storage of the 0-300 cm from booting stage to anthesis stage, significantly decrease the water storage of the 0-300 cm at mature stage, decrease the content of nitrate-nitrogen at the depth of 20 cm,60-80 cm,140 cm,180-220 cm and 280-300 cm at mature stage, increase the spike length, the bearing spikelet number, the grain protein and its component contents, Glu/Gli and the protein yield. Overall, the application of phosphorus 180 kg·hm-2 had better effect, the yield can reach 6101.00 kg·hm-2.(4) Whatever nitrogen fertilizer applicated in fallow period or before sowing, increased the nitrogen application amount from 75 kg·hm-2 to 255 kg·hm-2, the water storage of the 0-300 cm at different growth stages were increased, winter stage and turn-greening stage the soil water at depth of the 0-300 cm, elongation stage the soil water at depth of the 20-280 cm, booting stage and mature stage the soil water at depth of the 0-300 cm were all increased. Increased the nitrogen application decreased the consumption of water amount and significantly increased WUE, increased the leaf area and the dry biomass at different growth stage and bearing spikelet number. Increased the nitrogen application amount from 75 kg·hm-2 to 255 kg·hm-2, at mature stage the nitrogen accumulation amount of leaf firstly increased and then significantly decreased, the nitrogen accumulation amount of stem and sheath firstly decreased and then significantly increased, the nitrogen accumulation amount of glume and spike stem decreased, the nitrogen accumulation amount of grain and overground part significantly increased. Increased the nitrogen application amount, NABA and NAAA significantly increased, the contribution rate of NABA firstly decreased and then increased, he contribution rate of NAAA firstly increased and then decreased, NUE and NPFP significantly decreased, NHI significantly increased. Under the condition of subsoiling and nitrogen fertilizer applicated in fallow period, when the nitrogen application amount increased from 90 kg·hm-2 to 270 kg·hm-2, anthesis stage soil water at depth of the 0-300 cm were increased, the content of nitrate-nitrogen at the depth of 20-220 cm and 300 cm at mature stage were increased, the plant height at winter stage, turning-green stage, anthesis stage and mature stage were increased, spike length firstly decreased and then increased, the sterility spikelet number decreased, the remobilization of pre-anthesis stored nitrogen of different organs increased, the ear number, the 1000-grain weight and yield were significantly increased, the grain protein and its component contents, Glu/Gli and the protein yield were also increased.(5)Compared to nitrogen fertilizer applicated before sowing, nitrogen fertilizer applicated in fallow period can increase winter stage, turn-greening, elongation stage, booting stage and anthesis stage the soil water at depth of the 0-300 cm, decrease mature stage the soil water at depth of the 0-300 cm, significantly increase the consumption of water amount and WUE, increase the plant height at winter stage, anthesis stage and mature stage, increase the leaf area at different growth stage, increase nitrogen accumulation amount of leaf, glume and spike stem, grain, overground part at mature stage, significantly increased NUE, NPFP, NHI, the ear number, the 1000-grain weight and yield, increase the grain contents of Glutenin, Glu/Gli and protein yield.When nitrogen application was 255 kg·hm-2, compared to nitrogen fertilizer applicated before sowing, nitrogen fertilizer applicated in fallow period can decrease the content of nitrate-nitrogen at the depth of 20-80 cm,140 cm,180-220 cm and 160 cm at mature stage, increase the dry biomass at different growth stage, decrease the spike length and the sterility spikelet number, increase the bearing spikelet number, increase the remobilization of pre-anthesis stored nitrogen of leaf, glume and spike stem, vegetative organ, increase NABA and NAAA and its contribution rate, increase the grain contents of Globulin, Gliadin, decrease grain contents of Albumin. It had better effect when the application amount of nitrogen was 255 kg·hm-2 and applicated in fallow period, the yield can reach 6381.80 kg·hm-2. |
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