[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fe...[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fertilizer, respectively. After seedling transplanting, the biological characteristics of rice at different growth stages in each treatment and the biological and economic characteristics of rice after lodging were determined for statistical analysis. [Result] Application with 15 kg of nitrogen fertilizer had significant promotion effect on the increase of rice yield; compared with the control (6 kg of nitrogen fertilizer), rice yield in three experimental treatments (9, 12 and 15 kg of nitrogen fertilizer, respectively) increased by 50.74%, 89.11% and 94.48%, respectively; lodging-resistance mechanical strengths of the three experimental treatments were 103.97%, 132.01% and 89.83% of the control, respectively; rice lodging resistance of treatment C (12 kg of nitrogen fertilizer) was the strongest, with the highest yield. [Conclusion] This study provides reference data and technical support for the rational fertilization of rice production.展开更多
Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points fro...Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points from 1987 to 1990, it is found that intermittent cones of depression came into being due to groundwater exploitation in Guilin during the observation period. The buried depth of groundwater in the drawdown cones, the annual variation of water level and specific yield have higher values. Improvement has been made to the formula of infiltration coefficient of precipitation. By using the precipitation response data recorded at every 15 minutes for water level of No. 9 borehole which is near Zengpiyan Cave, the specific yield of phreatic variation zone is indirectly calculated by using the modified formula. The results are range from 0.012 to 0.462 and the spatial distribution of specific yield is ascertained. These make up the deficiency that empirical values cannot be categorized based on the actual conditions. What’s more, the widely used Aviriyanover’s empirical formula is poorly applicable to karst area. This is due to its strict requirement for outside conditions, such as shallow buried depth, homogeneous aquifer medium and small hydraulic gradient.展开更多
In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007....In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007. Some physiological indexes and yield ofD. styracifolium were compared among five nitrogen top-dressing levels （0, 37.5, 75.0, 112.5 and 150.0 kg N. hm-2）. Results showed that the nitrogen top-dressing could significantly increase the contents of chlorophyll, soluble protein, sucrose and nitrogen as well as nitrate reducase activity. However, there were no significant differences in most of these indexes under high nitrogen levels. Consistently, there was no significant difference in yield among nitrogen top-dressing levels of 75 kg N.hm-2, 112.5 kg N. hm-2 and 150 kg N-hm-2. Therefore, the optimum nitrogen top-dressing level ofD. styracifolium was 75 kg N. hm-2.展开更多
A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, Un...A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (Minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha<sup>-1</sup>. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha<sup>-1</sup> and 100 kg•ha<sup>-1</sup> respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. Maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha<sup>-1</sup>), grain yield (6.16 t•ha<sup>-1</sup>) and dried stalk yield (9.91 t•ha<sup>-1</sup>) were observed maximum in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha<sup>-1</sup> nitrogen application under the prevailing conditions of Faisalabad.展开更多
With decreasing availability of water for agriculture and increasing demand for rice production, an optimum use of irrigation water and phosphorus may guarantee sustainable rice production. Field experiments were cond...With decreasing availability of water for agriculture and increasing demand for rice production, an optimum use of irrigation water and phosphorus may guarantee sustainable rice production. Field experiments were conducted in 2003 and 2004 to investigate the effect of phosphorus and irrigation levels on yield, water productivity （WP）, phosphorus use efficiency （PUE） and income of low land rice. The experiment was laid out in randomized complete block design with split plot arrangements replicated four times. Main plot consisted of five phosphorus levels, viz. 0 （P0）, 50 （P50）, 100 （P100）, 150 （P15o）, and 200 （P200） kg/hm2, while subplots contained of irrigation times, i.e. 8 （I8）, 10 （I10）, 12 （I12）, and 14 （I14） irrigation levels, each with a water depth of 7.5 cm. Mean values revealed that P150 in combination with I10 produced the highest paddy yield （9.8 t/hm2） and net benefit （1 231.8 US$/hm2） among all the treatments. Phosphorus enhanced WP when applied in appropriate combination with irrigation level. The highest mean WP [13.3 kg/（hm2-mm）] could be achieved at Plso with 18 and decreased with increase in irrigation level, while the highest mean PUE （20.1 kg/kg） could be achieved at P100 with I10 and diminished with higher P levels. The overall results indicate that P150 along with I10 was the best combination for sustainable rice cultivation in silty clay soil.展开更多
In this greenhouse experiment, we investigated the effects of two constant groundwater levels: 10 cm groundwater level (GW-10) and 40 cm groundwater level (GW-40) and one change groundwater level, which was 40-10-40 c...In this greenhouse experiment, we investigated the effects of two constant groundwater levels: 10 cm groundwater level (GW-10) and 40 cm groundwater level (GW-40) and one change groundwater level, which was 40-10-40 cm (GW-40-10-40) on Cadmium (Cd) uptake and seed yield of Soybean plant in Cd contaminated soils (1.57 mg·kg-1). The experimental soil layer was made with gravel layer (14 cm), non-polluted soil (15 cm) and polluted soil (25 cm). The redox potential of every soil layer was measured from sowing to harvesting. The soil layer (10 – 40 cm) of GW-10 was always in reduction condition and that of GW-40 was always in oxidation condition. First 50 days of GW 40-10-40 were in oxidation and next 50 days in reduction and final 20 days again returned in oxidation condition. Soybean seed Cd concentration was significantly highest in GW-40-10-40 (1.16 ± 0.13 mg·kg-1) and lowest in GW-40 (0.81 ± 0.12 mg·kg-1). Cd concentration of stem was found significantly higher in GW-40 (1.7 ± 0.2 mg·kg-1) than GW-10 (0.91 ± 0.08 mg·kg-1) and GW-40-10-40 (1.28 ± 0.13 mg·kg-1). There was no significant difference in root Cd concentration among these 3 treatments. Main stem height of soybean plant and 100 seed weight of GW-40 were significantly higher than those of GW-10. The result revealed that, soil redox condition is an important factor for Cd uptake in soybean plant and seed yield of soybean. This study will help to manage the farming process more appropriately with the aim of minimizing uptake of Cd and other toxic metals in grain crops.展开更多
【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦...【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦后休闲(W)2种种植模式;副区为不施氮(N0)、氮肥减施30%(N1,157.5 kg N·hm^(-2))、当地习惯施氮(N2,225 kg N·hm^(-2))3个施氮水平,测定小麦产量及籽粒品质(籽粒蛋白、沉降值、形成时间、稳定时间、湿面筋等)。【结果】2023和2024年,W-GN1处理籽粒产量较WN1分别增加5.5%和13.4%,较WN2处理增加了2.0%和5.3%;W-GN1处理生物产量较WN1分别增加5.1%和10.6%,较WN2处理增加1.5%和4.6%。W-G较W处理能获得较高的收获指数。复种绿肥补偿效应在不施氮水平下呈负值,在施氮水平下为2.0%—14.0%,复种绿肥结合氮肥减施30%对增加作物产量的贡献最佳。同时,W-GN1处理可通过增加籽粒蛋白含量、沉降值、形成时间和稳定时间改善籽粒品质,其籽粒蛋白含量较WN1分别增加10.62%和9.48%;籽粒沉降值分别增加25.05%和18.13%;籽粒形成时间分别增加34.70%和8.66%;籽粒稳定时间分别增加41.30%和13.68%。通过主成分分析可知,麦后复种绿肥对籽粒蛋白含量、沉降值、形成时间和稳定时间的提升更为显著。【结论】麦后复种绿肥协同氮肥减施30%(N1,157.5 kg N·hm^(-2))显著提高了小麦籽粒产量,改善了籽粒品质,可作为青海省减施化肥条件下小麦提质稳产的适宜种植模式和施氮水平。展开更多
In the regions where crops were mostly produced by smallholder farmers, the analysis of yield gap is difficult due to diverse cultivars, crop managements and yield levels. In order to find an effective method that can...In the regions where crops were mostly produced by smallholder farmers, the analysis of yield gap is difficult due to diverse cultivars, crop managements and yield levels. In order to find an effective method that can reasonably verify the yield gap and the limiting cultivation factors in narrowing yield gaps in areas that are dominanted by smallholder farmers, we worked out a method consisting five progressive procedures as follows: questionnaire investigation of farmer cultivation regime, identification of yield levels and yield gaps, generalization of key cultivation measurements, reconstruction of representative maize populations, and process-based analysis of yield gap. A case study was carried out in Jiangsu Province, China, in which maize is mostly produced by smallholder farmers. A questionnaire investigation of 1 023 smallholder farmers was carried out firstly, then the frequency distribution of maize yield was simulated by an normal distribution function, and then the covering range and average value of the basic yield, farmer yield and high-yield farmer yield levels were calculated out from the equation. Hereby, the yield gaps 1, 2 and 3 were calculated along with the record highest yield from literature and experts, which were 2 564, 2 346 and 2 073 kg ha^(–1), respectively. Moreover, with the covering range of each yield level, the suveyed farmers belonging to each yield level were grouped together and then their major cultivation measures were traced and generalized. With the generalized cultivation measures, representative maize populations of the four yield levels were reconstructed, and thereby clarifing lots of characters of the populations or single plant of each population with processbased analysis of the reconstructed populations. In this case, the main factors causing the yield gap were plant density, fertilizer application rate, logging caused by hurricane, and damages caused by pests. The case study primarily indicated that this five-step method is feasible and effective in yield gap study, especially in smallholder farmers dominant regions.展开更多
【目的】探讨不同覆膜方式和磷水平对蚕豆光合特性、产量和水分利用效率的影响,为高寒地区蚕豆种植模式的选择和土壤养分管理提供数据支撑。【方法】于2020—2023年,在青海省东部以春蚕豆‘青海13号’为试验材料,采用随机区组试验设计,...【目的】探讨不同覆膜方式和磷水平对蚕豆光合特性、产量和水分利用效率的影响,为高寒地区蚕豆种植模式的选择和土壤养分管理提供数据支撑。【方法】于2020—2023年,在青海省东部以春蚕豆‘青海13号’为试验材料,采用随机区组试验设计,设置平作不覆膜(NMF)、全膜双垄沟播(DRM)、三垄全覆膜沟播(TRM)3种覆膜方式和3个磷水平(P0,不施肥;P1,9.1 kg P·hm^(-2);P2,18.2 kg P·hm^(-2)),研究不同覆膜方式和磷水平对土壤水热条件、蚕豆光合特性、产量和水分利用效率的影响。【结果】(1)相较于NMF处理,DRM和TRM处理提高蚕豆生育期10 cm土层土壤平均温度16.1%—20.5%和16.7%—23.0%,同时也提高了0—2 m土层土壤含水量和储水量。(2)相较于NMF处理,DRM和TRM处理降低蚕豆开花结荚期叶片蒸腾速率、气孔导度、胞间CO_(2)浓度、净光合速率和叶面积指数,并降低蚕豆籽粒产量、地上生物量和水分利用效率。NMF处理的年平均籽粒产量最高(2273 kg·hm^(-2)),其次是TRM处理(1030 kg·hm^(-2))和DRM处理(943 kg·hm^(-2))。(3)施磷提高NMF和DRM处理蚕豆开花结荚期净光合速率、蒸腾速率、胞间CO_(2)浓度、气孔导度和叶面积指数,并提高籽粒产量、地上生物量和水分利用效率,TRM处理的趋势则与之相反。(4)相关性分析表明,籽粒产量、地上生物量和水分利用效率,与净光合速率、蒸腾速率、胞间CO_(2)浓度、气孔导度、叶面积指数呈极显著正相关关系,与生育期土壤平均温度呈极显著负相关关系。【结论】垄沟地膜覆盖(DRM和TRM)抑制蚕豆生长后期的生长,叶面积指数增长速率减慢,光合作用减弱,导致籽粒产量、地上生物量和水分利用效率降低。在本试验条件下,平作不覆膜配施18.2 kg P·hm^(-2)磷肥显著增加光合面积,光合作用增强,从而提高蚕豆籽粒产量和水分利用效率,可作为提高高寒地区蚕豆生产力的有效措施。展开更多
Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at diff...Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.展开更多
文摘[Objective] This study aimed to investigate the effects of different fertilizer levels on lodging and yield of rice. [Method] A total of four treatments were designed and applied with 6, 9, 12 and 15 kg of nitrogen fertilizer, respectively. After seedling transplanting, the biological characteristics of rice at different growth stages in each treatment and the biological and economic characteristics of rice after lodging were determined for statistical analysis. [Result] Application with 15 kg of nitrogen fertilizer had significant promotion effect on the increase of rice yield; compared with the control (6 kg of nitrogen fertilizer), rice yield in three experimental treatments (9, 12 and 15 kg of nitrogen fertilizer, respectively) increased by 50.74%, 89.11% and 94.48%, respectively; lodging-resistance mechanical strengths of the three experimental treatments were 103.97%, 132.01% and 89.83% of the control, respectively; rice lodging resistance of treatment C (12 kg of nitrogen fertilizer) was the strongest, with the highest yield. [Conclusion] This study provides reference data and technical support for the rational fertilization of rice production.
基金supported by National Natural Science Foundation of China(No.41172231)
文摘Regime of groundwater level is a comprehensive reflection of the hydrogeological environment from the perspective of groundwater. Based on the analysis of the water-level change of 65 groundwater monitoring points from 1987 to 1990, it is found that intermittent cones of depression came into being due to groundwater exploitation in Guilin during the observation period. The buried depth of groundwater in the drawdown cones, the annual variation of water level and specific yield have higher values. Improvement has been made to the formula of infiltration coefficient of precipitation. By using the precipitation response data recorded at every 15 minutes for water level of No. 9 borehole which is near Zengpiyan Cave, the specific yield of phreatic variation zone is indirectly calculated by using the modified formula. The results are range from 0.012 to 0.462 and the spatial distribution of specific yield is ascertained. These make up the deficiency that empirical values cannot be categorized based on the actual conditions. What’s more, the widely used Aviriyanover’s empirical formula is poorly applicable to karst area. This is due to its strict requirement for outside conditions, such as shallow buried depth, homogeneous aquifer medium and small hydraulic gradient.
基金Supported by Scientifi c Research Foundation of Guangxi University (x061106)
文摘In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007. Some physiological indexes and yield ofD. styracifolium were compared among five nitrogen top-dressing levels （0, 37.5, 75.0, 112.5 and 150.0 kg N. hm-2）. Results showed that the nitrogen top-dressing could significantly increase the contents of chlorophyll, soluble protein, sucrose and nitrogen as well as nitrate reducase activity. However, there were no significant differences in most of these indexes under high nitrogen levels. Consistently, there was no significant difference in yield among nitrogen top-dressing levels of 75 kg N.hm-2, 112.5 kg N. hm-2 and 150 kg N-hm-2. Therefore, the optimum nitrogen top-dressing level ofD. styracifolium was 75 kg N. hm-2.
文摘A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (Minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha<sup>-1</sup>. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha<sup>-1</sup> and 100 kg•ha<sup>-1</sup> respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. Maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha<sup>-1</sup>), grain yield (6.16 t•ha<sup>-1</sup>) and dried stalk yield (9.91 t•ha<sup>-1</sup>) were observed maximum in deep tillage at 200 kg•ha<sup>-1</sup> nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha<sup>-1</sup> nitrogen application under the prevailing conditions of Faisalabad.
基金Gomal University, Dera IsmailKhan, Pakistan for partial support
文摘With decreasing availability of water for agriculture and increasing demand for rice production, an optimum use of irrigation water and phosphorus may guarantee sustainable rice production. Field experiments were conducted in 2003 and 2004 to investigate the effect of phosphorus and irrigation levels on yield, water productivity （WP）, phosphorus use efficiency （PUE） and income of low land rice. The experiment was laid out in randomized complete block design with split plot arrangements replicated four times. Main plot consisted of five phosphorus levels, viz. 0 （P0）, 50 （P50）, 100 （P100）, 150 （P15o）, and 200 （P200） kg/hm2, while subplots contained of irrigation times, i.e. 8 （I8）, 10 （I10）, 12 （I12）, and 14 （I14） irrigation levels, each with a water depth of 7.5 cm. Mean values revealed that P150 in combination with I10 produced the highest paddy yield （9.8 t/hm2） and net benefit （1 231.8 US$/hm2） among all the treatments. Phosphorus enhanced WP when applied in appropriate combination with irrigation level. The highest mean WP [13.3 kg/（hm2-mm）] could be achieved at Plso with 18 and decreased with increase in irrigation level, while the highest mean PUE （20.1 kg/kg） could be achieved at P100 with I10 and diminished with higher P levels. The overall results indicate that P150 along with I10 was the best combination for sustainable rice cultivation in silty clay soil.
文摘In this greenhouse experiment, we investigated the effects of two constant groundwater levels: 10 cm groundwater level (GW-10) and 40 cm groundwater level (GW-40) and one change groundwater level, which was 40-10-40 cm (GW-40-10-40) on Cadmium (Cd) uptake and seed yield of Soybean plant in Cd contaminated soils (1.57 mg·kg-1). The experimental soil layer was made with gravel layer (14 cm), non-polluted soil (15 cm) and polluted soil (25 cm). The redox potential of every soil layer was measured from sowing to harvesting. The soil layer (10 – 40 cm) of GW-10 was always in reduction condition and that of GW-40 was always in oxidation condition. First 50 days of GW 40-10-40 were in oxidation and next 50 days in reduction and final 20 days again returned in oxidation condition. Soybean seed Cd concentration was significantly highest in GW-40-10-40 (1.16 ± 0.13 mg·kg-1) and lowest in GW-40 (0.81 ± 0.12 mg·kg-1). Cd concentration of stem was found significantly higher in GW-40 (1.7 ± 0.2 mg·kg-1) than GW-10 (0.91 ± 0.08 mg·kg-1) and GW-40-10-40 (1.28 ± 0.13 mg·kg-1). There was no significant difference in root Cd concentration among these 3 treatments. Main stem height of soybean plant and 100 seed weight of GW-40 were significantly higher than those of GW-10. The result revealed that, soil redox condition is an important factor for Cd uptake in soybean plant and seed yield of soybean. This study will help to manage the farming process more appropriately with the aim of minimizing uptake of Cd and other toxic metals in grain crops.
文摘【目的】探明麦后复种绿肥协同不同水平氮肥对春小麦产量和籽粒品质的影响,对构建青海省基于绿肥的化肥减施与优质生产模式提供理论指导。【方法】于2023—2024年在青海大学农林科学院试验地进行裂区试验,主区为麦后复种绿肥(W-G)和麦后休闲(W)2种种植模式;副区为不施氮(N0)、氮肥减施30%(N1,157.5 kg N·hm^(-2))、当地习惯施氮(N2,225 kg N·hm^(-2))3个施氮水平,测定小麦产量及籽粒品质(籽粒蛋白、沉降值、形成时间、稳定时间、湿面筋等)。【结果】2023和2024年,W-GN1处理籽粒产量较WN1分别增加5.5%和13.4%,较WN2处理增加了2.0%和5.3%;W-GN1处理生物产量较WN1分别增加5.1%和10.6%,较WN2处理增加1.5%和4.6%。W-G较W处理能获得较高的收获指数。复种绿肥补偿效应在不施氮水平下呈负值,在施氮水平下为2.0%—14.0%,复种绿肥结合氮肥减施30%对增加作物产量的贡献最佳。同时,W-GN1处理可通过增加籽粒蛋白含量、沉降值、形成时间和稳定时间改善籽粒品质,其籽粒蛋白含量较WN1分别增加10.62%和9.48%;籽粒沉降值分别增加25.05%和18.13%;籽粒形成时间分别增加34.70%和8.66%;籽粒稳定时间分别增加41.30%和13.68%。通过主成分分析可知,麦后复种绿肥对籽粒蛋白含量、沉降值、形成时间和稳定时间的提升更为显著。【结论】麦后复种绿肥协同氮肥减施30%(N1,157.5 kg N·hm^(-2))显著提高了小麦籽粒产量,改善了籽粒品质,可作为青海省减施化肥条件下小麦提质稳产的适宜种植模式和施氮水平。
基金funded by the National Key Research and Development Program of China(2016YFD0300109)。
文摘In the regions where crops were mostly produced by smallholder farmers, the analysis of yield gap is difficult due to diverse cultivars, crop managements and yield levels. In order to find an effective method that can reasonably verify the yield gap and the limiting cultivation factors in narrowing yield gaps in areas that are dominanted by smallholder farmers, we worked out a method consisting five progressive procedures as follows: questionnaire investigation of farmer cultivation regime, identification of yield levels and yield gaps, generalization of key cultivation measurements, reconstruction of representative maize populations, and process-based analysis of yield gap. A case study was carried out in Jiangsu Province, China, in which maize is mostly produced by smallholder farmers. A questionnaire investigation of 1 023 smallholder farmers was carried out firstly, then the frequency distribution of maize yield was simulated by an normal distribution function, and then the covering range and average value of the basic yield, farmer yield and high-yield farmer yield levels were calculated out from the equation. Hereby, the yield gaps 1, 2 and 3 were calculated along with the record highest yield from literature and experts, which were 2 564, 2 346 and 2 073 kg ha^(–1), respectively. Moreover, with the covering range of each yield level, the suveyed farmers belonging to each yield level were grouped together and then their major cultivation measures were traced and generalized. With the generalized cultivation measures, representative maize populations of the four yield levels were reconstructed, and thereby clarifing lots of characters of the populations or single plant of each population with processbased analysis of the reconstructed populations. In this case, the main factors causing the yield gap were plant density, fertilizer application rate, logging caused by hurricane, and damages caused by pests. The case study primarily indicated that this five-step method is feasible and effective in yield gap study, especially in smallholder farmers dominant regions.
文摘【目的】探讨不同覆膜方式和磷水平对蚕豆光合特性、产量和水分利用效率的影响,为高寒地区蚕豆种植模式的选择和土壤养分管理提供数据支撑。【方法】于2020—2023年,在青海省东部以春蚕豆‘青海13号’为试验材料,采用随机区组试验设计,设置平作不覆膜(NMF)、全膜双垄沟播(DRM)、三垄全覆膜沟播(TRM)3种覆膜方式和3个磷水平(P0,不施肥;P1,9.1 kg P·hm^(-2);P2,18.2 kg P·hm^(-2)),研究不同覆膜方式和磷水平对土壤水热条件、蚕豆光合特性、产量和水分利用效率的影响。【结果】(1)相较于NMF处理,DRM和TRM处理提高蚕豆生育期10 cm土层土壤平均温度16.1%—20.5%和16.7%—23.0%,同时也提高了0—2 m土层土壤含水量和储水量。(2)相较于NMF处理,DRM和TRM处理降低蚕豆开花结荚期叶片蒸腾速率、气孔导度、胞间CO_(2)浓度、净光合速率和叶面积指数,并降低蚕豆籽粒产量、地上生物量和水分利用效率。NMF处理的年平均籽粒产量最高(2273 kg·hm^(-2)),其次是TRM处理(1030 kg·hm^(-2))和DRM处理(943 kg·hm^(-2))。(3)施磷提高NMF和DRM处理蚕豆开花结荚期净光合速率、蒸腾速率、胞间CO_(2)浓度、气孔导度和叶面积指数,并提高籽粒产量、地上生物量和水分利用效率,TRM处理的趋势则与之相反。(4)相关性分析表明,籽粒产量、地上生物量和水分利用效率,与净光合速率、蒸腾速率、胞间CO_(2)浓度、气孔导度、叶面积指数呈极显著正相关关系,与生育期土壤平均温度呈极显著负相关关系。【结论】垄沟地膜覆盖(DRM和TRM)抑制蚕豆生长后期的生长,叶面积指数增长速率减慢,光合作用减弱,导致籽粒产量、地上生物量和水分利用效率降低。在本试验条件下,平作不覆膜配施18.2 kg P·hm^(-2)磷肥显著增加光合面积,光合作用增强,从而提高蚕豆籽粒产量和水分利用效率,可作为提高高寒地区蚕豆生产力的有效措施。
基金Supported by Earmarked Fund for Modern Agro-industry Technology of China(CARS-01-25)National Key Research and Development Program of China(2017YFD0301705)Foundation of Youth Science Program of Sichuan Agricultural Sciences Academy(2019QNJJ-020)。
文摘Increased plant density with low N rate was a recommended strategy to increase grain yield and N use efficiency(NUE);however,grain yield,NUE and the total N uptake(TNU)responses of hybrid rice to this strategy at different yield levels(medium yielding site(MYS)Luzhou City and high yielding site(HYS)Deyang City had not been described.Field experiments with hybrid rice Rongyou1015 were conducted to study the effects of two plant densities.High plant density(HD),low plant density(LD)and four N rates(without N,N_(0);a recommended N rate of 195 kg•hm^(-2),N_(CK);a 23%reduction in N rate,N_(-23%);a 46%reduction in N rate,N_(-46%)on yield attributes,grain yield,TNU and NUE of hybrid rice were studied under different yield levels in 2016-2017.The results showed that the grain yield and NUE of hybrid rice in response to plant density and N rate varied with yield levels.For MYS,reducing N rate by 46%result in significantly lower grain yield at LD treatment;whereas at HD treatment the grain yield of hybrid rice under N_(-46%) and N_(CK) were equal.For HYS,reducing N rate by 46% result in significantly lower grain yield regardless of low plant density and high plant density;however,a reduction in N rate by 23%increased grain yield,AE_(N) by 36%,PFP_(N) by 31% and RE_(N) by 11% over N_(CK) at HD treatment.Higher grain yield of hybrid rice under the combination of HD with low N rate was attributable to improvement in spikelets per panicle and harvest index.The results suggested that high plant density with low N rate might be an effective approach to improve grain yield and NUE in rice production,but reduction in N application rate was determined,according to yield levels.
