Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Su...Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Supplemental irrigation had three levels: 60%(W_1),70%(W_2) and 80%(W3) of the targeted relative water content at 0-40 cm of soil layer during jointing period of winter wheat.Nitrogen fertilization had three levels: not using nitrogen(N_0),using pure nitrogen of 195 kg/hm^2(N_(195)) and 255 kg/hm^2(N_(255)).Results showed that:(i)different supplemental irrigation and nitrogen fertilization significantly affected plant height and leaf area of winter wheat during key growth period.Under the same supplemental irrigation treatment,both plant height and leaf area of winter wheat showed as N_(255)> N_(195)> N_0(P <0.05).Plant height in N_(195) and N_(255)treatments was significantly higher than that in N_0 treatment,but there was not significant difference between N_(195) and N_(255)(P >0.05).Under the same nitrogen fertilization,plant height in W_2(569.4 m^3/hm^2) and W3(873.45 m^3/hm^2) treatments was significant higher than that in W_1(265.2 m^3/hm^2),but there was not significant difference between W_2 and W3(P >0.05).It illustrated that excessive nitrogen fertilization and supplemental irrigation did not significantly affect plant height and leaf area of winter wheat.(ii) Under the same nitrogen fertilization level,yield increase effect of winter wheat by supplemental irrigation showed a declining trend with nitrogen application amount increased.It illustrated that nitrogen fertilization and supplemental irrigation had certain critical values on the yield of winter wheat.When surpassing the critical value,the yield declined.When nitrogen fertilization amount was 195 kg/hm^2,and supplemental irrigation amount was 70% of field moisture capacity(569.4 m^3/hm^2),the highest yield 8500 kg/hm^2 could be obtained.(iii) During mature period of winter wheat,nitrogen accumulation amount of plant treated by nitrogen was significantly higher than that not treated by nitrogen(P <0.05).But under the treatments of W_2 and W3,nitrogen accumulation amount in N_(255) significantly declined when compared with N_(195)(P <0.05).Especially under W3(873.45 m^3/hm^2) level,nitrogen accumulation amount in N_(255) was even lower than N_0.Under the treatments of N_0 and N_(195),nitrogen accumulation amount of plant significantly increased with supplemental irrigation increased(P < 0.05).But under N_(255) treatment,there was not significant difference(P > 0.05).It illustrated that moderate supplemental irrigation and nitrogen fertilization could improve nitrogen absorption ability of winter wheat,but excessive supplemental irrigation and nitrogen fertilization were not favorable for plant's nitrogen absorption.(iv) Although the increase of supplemental irrigation during jointing period improved nitrogen absorption ability of winter wheat and promoted winter wheat absorbing more nitrogen,it inhibited nitrogen transferring and distributing to seed.Comprehensively considering growth condition of winter wheat and nitrogen risk condition,it is suggested that nitrogen application amount was 195 kg/hm^2,and supplemental irrigation reached 70% of field moisture capacity(569.4 m^3/hm^2),which could be as the suitable water and fertilizer use amounts in the region.展开更多
Deep placement of controlled-release fertilizer increases nitrogen (N) use efficiency in rice planting but is expensive. Few studies on direct-seeded rice have examined the effects of deep placement of conventional fe...Deep placement of controlled-release fertilizer increases nitrogen (N) use efficiency in rice planting but is expensive. Few studies on direct-seeded rice have examined the effects of deep placement of conventional fertilizer. With prilled urea serving as N fertilizer, a two-year field experiment with two N rates (120 and 195 kg/hm2) and four basal N application treatments (B50, all fertilizer was broadcast with 50% as basal N;D50, D70 and D100 corresponded to 50%, 70% and 100% of N deeply placed as basal N, respectively) were conducted in direct-seeded rice in 2013 and 2014. Soil N distribution and plant N uptake were analyzed. The results showed that deep placement of basal N significantly increased total N concentrations in soil. Significantly greater soil N concentrations were observed in D100 compared with B50 at 0, 6 and 12 cm (lateral distance) from the fertilizer application point both at mid-tillering and heading stages. D100 presented the highest values of dry matter and N accumulation from seeding to mid-tillering stages, but it presented the lowest values from heading to maturity stages and the lowest grain yield for no sufficient N supply at the reproductive stage. The grain yield of D50 was the highest, however, no significant difference was observed in grain yield, N agronomic efficiency or N recovery efficiency between D70 and D50, or between D70 and B50, while D70 was more labor saving than D50 for only one topdressing was applied in D70 compared with twice in other treatments. The above results indicated that 70% of fertilizer-N deeply placed as a basal fertilizer and 30% of fertilizer-N topdressed as a panicle fertilizer constituted an ideal approach for direct-seeded rice. This recommendation was further verified through on-farm demonstration experiments in 2015, in which D70 produced in similar grain yields as B50 did.展开更多
In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in t...In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in ten rice genotypes were investgated at the elongation, booting, heading and maturity stages under six N levels in a pot experiment with soil-sand mixtures at various ratios. NAE in various rice genotypes firstly increased, peaked under a medium nitrogen rate of 0.177 g/kg and then decreased, but NUE and NHI always decreased with increasing nitrogen levels. NAE in various rice genotypes ever increased with growing process and NUE indicated a descending tendency of elongation stage〉heading stage〉maturity stage〉booting stage. N level influenced rice NAE, NUE and NHI most, followed by genotype, and the both effects were significant at 0.01 level. In addition, the interaction effects of genotype and nitrogen level on rice NAE and NUE were significant at 0.01 level, but not significant on rice NHI. Because the maximum differences of NAE and NUE were found at the elongation stage, it was thought to be the most suitable stage for identification and screening these two paremeters. Therefore, the optimum conditions for identification and screening of rice NAE, NUE and NHI in a pot experiment were the nitrogen rate of 0.157 g/kg at the elongation stage, low nitrogen at the elongation stage, and the nitrogen rate of 0.277 g/kg at the maturity stage, respectively.展开更多
To evaluate the effects of nitrogen(N)and irrigation coupling on the soil N distribution,plant N utilization,and fruit yield of rabbiteye blueberries(Vaccinium virgatum),a field experiment was designed using two facto...To evaluate the effects of nitrogen(N)and irrigation coupling on the soil N distribution,plant N utilization,and fruit yield of rabbiteye blueberries(Vaccinium virgatum),a field experiment was designed using two factors(water and fertilizer application)with four levels of irrigation and three levels of fertilization,and a control.Under the different water and fertilizer combinations,N primarily accumulated in the leaves.Irrigation and N application within appropriate ranges(pure N≤29 g/plant and irrigation volume≤2.5 L/plant)significantly improved the blueberry fruit yield.Increases in water and N within these ranges promoted the effective accumulation of N in various organs and the absorption and utilization of N in the plants,which ultimately promoted blueberry yield.With increased N application rate,the nitrate N content of the 0–20 cm and 20–50 cm soil layers increased.With increased irrigation volume,the nitrate N content of the 0–20 cm soil layer decreased,while the nitrate content in the 20–50 cm soil layer increased.Low N and moderate water treatments resulted in high fruit yields and reduced nitrate N retention in the soil.Under these conditions,the economic input-output ratio was high and the soil N accumulation was low,and thus the economic and ecological benefits were maximized.展开更多
Wheat is a staple crop worldwide, but yields may diminish as climate change causes increasingly unpredictable patterns of precipitation and soil nutrient availability. Farmers are thus challenged to maximize planting ...Wheat is a staple crop worldwide, but yields may diminish as climate change causes increasingly unpredictable patterns of precipitation and soil nutrient availability. Farmers are thus challenged to maximize planting efficiency to increase yield, while also improving their resource use efficiency. In this study the effectiveness of tridimensional uniform sowing was tested across a range of planting densities for winter wheat crops on the North China Plain. Tridimensional uniform sowing was tested against conventional drilling at three planting densities (180 × 104, 270 × 104, and 360 × 104 plants ha 1) and assessed for water consumption, biomass, nitrogen uptake and allocation, and aspects of yield. The tridimensional uniform sowing treatment outperformed the conventional drilling treatment in most metrics and at most planting densities, while performing markedly better at higher planting densities. Water consumption decreased and nitrogen efficiency increased. Tiller number and percentage of productive tillers, leaf area index, dry weight, and yield increased without a significant decline in grain protein. Nitrogen allocation was more efficient under tridimensional uniform sowing than with conventional drilling, and also varied according to annual precipitation and planting density. Both yield and grain protein contents were significantly correlated with the amount of pre-anthesis accumu- lated nitrogen translocated from vegetative organs to kernels after anthesis. Overall, a density of 270 × 104 plants ha 1 provided the highest water use efficiency and grain yield. Tridimensional uniform sowing will benefit farmers by forming stronger overall crops, promoting the coordinated improvement of yield, nitrogen uptake and efficiency, and increasing grain protein content at higher planting densities.展开更多
为研究不同施氮量对黑小麦产量、干物质积累及氮素吸收利用的影响,试验以黑小麦品种‘农大876’和‘冀紫439’为供试材料,于2021—2023年在田间设置不施氮和分别施氮120、180、240 kg N/hm^(2)处理,于各生长期测定产量要素及各器官含氮...为研究不同施氮量对黑小麦产量、干物质积累及氮素吸收利用的影响,试验以黑小麦品种‘农大876’和‘冀紫439’为供试材料,于2021—2023年在田间设置不施氮和分别施氮120、180、240 kg N/hm^(2)处理,于各生长期测定产量要素及各器官含氮量。结果表明:增加施氮量提高黑小麦产量主要是由于提高了穗数和收获指数,但品种间存在差异。对于‘农大876’,施氮180 kg N/hm^(2)产量最高,与不施氮处理相比显著提高13.0%;‘冀紫439’施氮180 kg N/hm^(2)和240 kg N/hm^(2)产量与不施氮处理相比均提高48.8%。提高施氮量,有利于提高黑小麦地上部吸氮量和干物质积累量,但品种间存在显著差异。‘农大876’、‘冀紫439’于拔节期追肥后,地上部干物质积累量分别增加72.9%~128.4%、131.5%~215.2%,表明‘冀紫439’对氮肥的响应更为敏感。增施氮肥对氮素收获指数无显著影响,但均不利于提高两个黑小麦品种的氮素吸收效率、氮素利用效率、氮肥偏生产力。因此,在与本研究土壤环境一致的条件下,对于‘农大876’这类相对高杆且低养分需求的黑小麦品种,其最高产量推荐施氮量为199 kg N/hm^(2);而对于‘冀紫439’这类对氮肥响应更敏感的黑小麦品种,其最高产量推荐施氮量为211 kg N/hm^(2)。展开更多
水分和氮素对水稻叶片光合特性和氮素吸收利用有重要影响,但在干湿交替灌溉条件下,水、氮是如何影响水稻叶片和根系氮代谢酶活性、产量和氮素吸收利用的仍不清楚。探明这一问题对于协同提高产量和氮肥利用效率有重要意义。本研究以超级...水分和氮素对水稻叶片光合特性和氮素吸收利用有重要影响,但在干湿交替灌溉条件下,水、氮是如何影响水稻叶片和根系氮代谢酶活性、产量和氮素吸收利用的仍不清楚。探明这一问题对于协同提高产量和氮肥利用效率有重要意义。本研究以超级稻品种南粳9108为材料,大田种植,设置全生育期常规灌溉(conventional irrigation,CI)和干湿交替灌溉(alternate wetting and drying irrigation,AWD)2种灌溉方式及5个施氮水平,不施氮(N0)、施氮90 kg hm^(-2)(N1)、施氮180 kg hm^(-2)(N2)、施氮270 kg hm^(-2)(N3)和施氮360 kg hm^(-2)(N4)。结果表明,与CI相比,AWD增加了水稻主要生育时期叶片的叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量,提高了叶片净光合速率,并显著增加了叶片中超氧化物歧化酶、过氧化氢酶、硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶活性,显著降低了过氧化物酶、内肽酶活性和丙二醛含量,显著提高了根系中氮代谢酶硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶和谷氨酸脱氢酶活性;AWD的产量较CI平均增加了10.4%。AWD显著提高了氮素转运量、氮素转运率、氮肥吸收利用率和氮肥偏生产力,产量和氮肥利用率均以AWD+N3处理组合的最高。因此,轻度干湿交替灌溉配合一定的施氮量,可以充分发挥水、肥效应,促进根系和叶片的氮代谢水平,提高叶片光合特性,协调地下地上部生长,有利于水稻产量和氮肥利用率的协同提高。展开更多
基金Supported by National Key Research Plan Project(2016YFD0801001,2016YFD0200103,2017YFD0800500)
文摘Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Supplemental irrigation had three levels: 60%(W_1),70%(W_2) and 80%(W3) of the targeted relative water content at 0-40 cm of soil layer during jointing period of winter wheat.Nitrogen fertilization had three levels: not using nitrogen(N_0),using pure nitrogen of 195 kg/hm^2(N_(195)) and 255 kg/hm^2(N_(255)).Results showed that:(i)different supplemental irrigation and nitrogen fertilization significantly affected plant height and leaf area of winter wheat during key growth period.Under the same supplemental irrigation treatment,both plant height and leaf area of winter wheat showed as N_(255)> N_(195)> N_0(P <0.05).Plant height in N_(195) and N_(255)treatments was significantly higher than that in N_0 treatment,but there was not significant difference between N_(195) and N_(255)(P >0.05).Under the same nitrogen fertilization,plant height in W_2(569.4 m^3/hm^2) and W3(873.45 m^3/hm^2) treatments was significant higher than that in W_1(265.2 m^3/hm^2),but there was not significant difference between W_2 and W3(P >0.05).It illustrated that excessive nitrogen fertilization and supplemental irrigation did not significantly affect plant height and leaf area of winter wheat.(ii) Under the same nitrogen fertilization level,yield increase effect of winter wheat by supplemental irrigation showed a declining trend with nitrogen application amount increased.It illustrated that nitrogen fertilization and supplemental irrigation had certain critical values on the yield of winter wheat.When surpassing the critical value,the yield declined.When nitrogen fertilization amount was 195 kg/hm^2,and supplemental irrigation amount was 70% of field moisture capacity(569.4 m^3/hm^2),the highest yield 8500 kg/hm^2 could be obtained.(iii) During mature period of winter wheat,nitrogen accumulation amount of plant treated by nitrogen was significantly higher than that not treated by nitrogen(P <0.05).But under the treatments of W_2 and W3,nitrogen accumulation amount in N_(255) significantly declined when compared with N_(195)(P <0.05).Especially under W3(873.45 m^3/hm^2) level,nitrogen accumulation amount in N_(255) was even lower than N_0.Under the treatments of N_0 and N_(195),nitrogen accumulation amount of plant significantly increased with supplemental irrigation increased(P < 0.05).But under N_(255) treatment,there was not significant difference(P > 0.05).It illustrated that moderate supplemental irrigation and nitrogen fertilization could improve nitrogen absorption ability of winter wheat,but excessive supplemental irrigation and nitrogen fertilization were not favorable for plant's nitrogen absorption.(iv) Although the increase of supplemental irrigation during jointing period improved nitrogen absorption ability of winter wheat and promoted winter wheat absorbing more nitrogen,it inhibited nitrogen transferring and distributing to seed.Comprehensively considering growth condition of winter wheat and nitrogen risk condition,it is suggested that nitrogen application amount was 195 kg/hm^2,and supplemental irrigation reached 70% of field moisture capacity(569.4 m^3/hm^2),which could be as the suitable water and fertilizer use amounts in the region.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFD0300108)the National Natural Science Foundation of China(Grant Nos.31671630 and 31371581)the National Rice Industry Technology System(CARS-01-04A)in China
文摘Deep placement of controlled-release fertilizer increases nitrogen (N) use efficiency in rice planting but is expensive. Few studies on direct-seeded rice have examined the effects of deep placement of conventional fertilizer. With prilled urea serving as N fertilizer, a two-year field experiment with two N rates (120 and 195 kg/hm2) and four basal N application treatments (B50, all fertilizer was broadcast with 50% as basal N;D50, D70 and D100 corresponded to 50%, 70% and 100% of N deeply placed as basal N, respectively) were conducted in direct-seeded rice in 2013 and 2014. Soil N distribution and plant N uptake were analyzed. The results showed that deep placement of basal N significantly increased total N concentrations in soil. Significantly greater soil N concentrations were observed in D100 compared with B50 at 0, 6 and 12 cm (lateral distance) from the fertilizer application point both at mid-tillering and heading stages. D100 presented the highest values of dry matter and N accumulation from seeding to mid-tillering stages, but it presented the lowest values from heading to maturity stages and the lowest grain yield for no sufficient N supply at the reproductive stage. The grain yield of D50 was the highest, however, no significant difference was observed in grain yield, N agronomic efficiency or N recovery efficiency between D70 and D50, or between D70 and B50, while D70 was more labor saving than D50 for only one topdressing was applied in D70 compared with twice in other treatments. The above results indicated that 70% of fertilizer-N deeply placed as a basal fertilizer and 30% of fertilizer-N topdressed as a panicle fertilizer constituted an ideal approach for direct-seeded rice. This recommendation was further verified through on-farm demonstration experiments in 2015, in which D70 produced in similar grain yields as B50 did.
基金supported by the National High-Tech Research&Development program(Grant No.2003AA206030)the National Natural Science Foundation of China(Grant No.30030090)
文摘In order to establish methods for indentification and screening of rice genotypes with high nitrogen （N） efficiency, N absorption efficiency （NAE）, N utilization efficiency （NUE） and N harvest index （NHI） in ten rice genotypes were investgated at the elongation, booting, heading and maturity stages under six N levels in a pot experiment with soil-sand mixtures at various ratios. NAE in various rice genotypes firstly increased, peaked under a medium nitrogen rate of 0.177 g/kg and then decreased, but NUE and NHI always decreased with increasing nitrogen levels. NAE in various rice genotypes ever increased with growing process and NUE indicated a descending tendency of elongation stage〉heading stage〉maturity stage〉booting stage. N level influenced rice NAE, NUE and NHI most, followed by genotype, and the both effects were significant at 0.01 level. In addition, the interaction effects of genotype and nitrogen level on rice NAE and NUE were significant at 0.01 level, but not significant on rice NHI. Because the maximum differences of NAE and NUE were found at the elongation stage, it was thought to be the most suitable stage for identification and screening these two paremeters. Therefore, the optimum conditions for identification and screening of rice NAE, NUE and NHI in a pot experiment were the nitrogen rate of 0.157 g/kg at the elongation stage, low nitrogen at the elongation stage, and the nitrogen rate of 0.277 g/kg at the maturity stage, respectively.
基金funded by the National Natural Science Foundation of China(NSFC 31260192)the Major Projects in Guizhou Province(SY[2015]6032-2)。
文摘To evaluate the effects of nitrogen(N)and irrigation coupling on the soil N distribution,plant N utilization,and fruit yield of rabbiteye blueberries(Vaccinium virgatum),a field experiment was designed using two factors(water and fertilizer application)with four levels of irrigation and three levels of fertilization,and a control.Under the different water and fertilizer combinations,N primarily accumulated in the leaves.Irrigation and N application within appropriate ranges(pure N≤29 g/plant and irrigation volume≤2.5 L/plant)significantly improved the blueberry fruit yield.Increases in water and N within these ranges promoted the effective accumulation of N in various organs and the absorption and utilization of N in the plants,which ultimately promoted blueberry yield.With increased N application rate,the nitrate N content of the 0–20 cm and 20–50 cm soil layers increased.With increased irrigation volume,the nitrate N content of the 0–20 cm soil layer decreased,while the nitrate content in the 20–50 cm soil layer increased.Low N and moderate water treatments resulted in high fruit yields and reduced nitrate N retention in the soil.Under these conditions,the economic input-output ratio was high and the soil N accumulation was low,and thus the economic and ecological benefits were maximized.
基金supported by the National Key Research and Development Program of China (2016YFD0300407)Earmarked Fund for China Agriculture Research System (CARS-03)Agricultural Technology Test Demonstration and Service Support (118003)
文摘Wheat is a staple crop worldwide, but yields may diminish as climate change causes increasingly unpredictable patterns of precipitation and soil nutrient availability. Farmers are thus challenged to maximize planting efficiency to increase yield, while also improving their resource use efficiency. In this study the effectiveness of tridimensional uniform sowing was tested across a range of planting densities for winter wheat crops on the North China Plain. Tridimensional uniform sowing was tested against conventional drilling at three planting densities (180 × 104, 270 × 104, and 360 × 104 plants ha 1) and assessed for water consumption, biomass, nitrogen uptake and allocation, and aspects of yield. The tridimensional uniform sowing treatment outperformed the conventional drilling treatment in most metrics and at most planting densities, while performing markedly better at higher planting densities. Water consumption decreased and nitrogen efficiency increased. Tiller number and percentage of productive tillers, leaf area index, dry weight, and yield increased without a significant decline in grain protein. Nitrogen allocation was more efficient under tridimensional uniform sowing than with conventional drilling, and also varied according to annual precipitation and planting density. Both yield and grain protein contents were significantly correlated with the amount of pre-anthesis accumu- lated nitrogen translocated from vegetative organs to kernels after anthesis. Overall, a density of 270 × 104 plants ha 1 provided the highest water use efficiency and grain yield. Tridimensional uniform sowing will benefit farmers by forming stronger overall crops, promoting the coordinated improvement of yield, nitrogen uptake and efficiency, and increasing grain protein content at higher planting densities.
文摘为研究不同施氮量对黑小麦产量、干物质积累及氮素吸收利用的影响,试验以黑小麦品种‘农大876’和‘冀紫439’为供试材料,于2021—2023年在田间设置不施氮和分别施氮120、180、240 kg N/hm^(2)处理,于各生长期测定产量要素及各器官含氮量。结果表明:增加施氮量提高黑小麦产量主要是由于提高了穗数和收获指数,但品种间存在差异。对于‘农大876’,施氮180 kg N/hm^(2)产量最高,与不施氮处理相比显著提高13.0%;‘冀紫439’施氮180 kg N/hm^(2)和240 kg N/hm^(2)产量与不施氮处理相比均提高48.8%。提高施氮量,有利于提高黑小麦地上部吸氮量和干物质积累量,但品种间存在显著差异。‘农大876’、‘冀紫439’于拔节期追肥后,地上部干物质积累量分别增加72.9%~128.4%、131.5%~215.2%,表明‘冀紫439’对氮肥的响应更为敏感。增施氮肥对氮素收获指数无显著影响,但均不利于提高两个黑小麦品种的氮素吸收效率、氮素利用效率、氮肥偏生产力。因此,在与本研究土壤环境一致的条件下,对于‘农大876’这类相对高杆且低养分需求的黑小麦品种,其最高产量推荐施氮量为199 kg N/hm^(2);而对于‘冀紫439’这类对氮肥响应更敏感的黑小麦品种,其最高产量推荐施氮量为211 kg N/hm^(2)。
文摘水分和氮素对水稻叶片光合特性和氮素吸收利用有重要影响,但在干湿交替灌溉条件下,水、氮是如何影响水稻叶片和根系氮代谢酶活性、产量和氮素吸收利用的仍不清楚。探明这一问题对于协同提高产量和氮肥利用效率有重要意义。本研究以超级稻品种南粳9108为材料,大田种植,设置全生育期常规灌溉(conventional irrigation,CI)和干湿交替灌溉(alternate wetting and drying irrigation,AWD)2种灌溉方式及5个施氮水平,不施氮(N0)、施氮90 kg hm^(-2)(N1)、施氮180 kg hm^(-2)(N2)、施氮270 kg hm^(-2)(N3)和施氮360 kg hm^(-2)(N4)。结果表明,与CI相比,AWD增加了水稻主要生育时期叶片的叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量,提高了叶片净光合速率,并显著增加了叶片中超氧化物歧化酶、过氧化氢酶、硝酸还原酶、谷氨酰胺合成酶和谷氨酸合成酶活性,显著降低了过氧化物酶、内肽酶活性和丙二醛含量,显著提高了根系中氮代谢酶硝酸还原酶、谷氨酰胺合成酶、谷氨酸合成酶和谷氨酸脱氢酶活性;AWD的产量较CI平均增加了10.4%。AWD显著提高了氮素转运量、氮素转运率、氮肥吸收利用率和氮肥偏生产力,产量和氮肥利用率均以AWD+N3处理组合的最高。因此,轻度干湿交替灌溉配合一定的施氮量,可以充分发挥水、肥效应,促进根系和叶片的氮代谢水平,提高叶片光合特性,协调地下地上部生长,有利于水稻产量和氮肥利用率的协同提高。
