Fate of urea nitrogen (N) applied to rape grown on a red soil was investigated by the ￣(15)N mass balancetechnique, and efficiency of urea and effect of nutrients balance in raising rape yield were investigated ina f...Fate of urea nitrogen (N) applied to rape grown on a red soil was investigated by the ￣(15)N mass balancetechnique, and efficiency of urea and effect of nutrients balance in raising rape yield were investigated ina field plot experiment. One hundred and thirty-eight kg N/ha, 86 kg N/ha as basal dressing and 52 kgN/ha as top dressing, was applied with band application technique. The experiment was conducted in thesoutheast of China, near Yingtan City, Jianxi Province.Results from is￣(15)N mass balance study showed that when urea was applied as basal dressing the plantrecovery was 44.0% of the applied N for Theatment T (with application of N, P, K, B and lime). Plantrecoveries were 38.0%-40.5% for Treatments -K, -B, -lime and +RS (without application of K, B or limeas well as with additional rice straw compared with Theatment T), which were not significantly differentfrom Treatment T. In contrast, plant recovery was only 5.1% for Treatment-P (without application of P),indicating that P was the factor limiting N uptake by rape. However, N remaining in 0-0.30 m soil was highup to 71.6% for Theatment -P, while the corresponding data were 33.0%-42.6% for the other treatments.The total recovery of applied N (including plant recovery and N remaining in 0-0.60 m soil) was 91.5% forTreatment T when urea was applied as basal dressing, while almost all the applied N was recovered when ureawas applied as top dressing. It was suggested that N loss was greatly controlled by using band applicationmethod in this experiment.Results from the field plot experiment showed that N supply capacity of this red soil was very low, andthe efficiency of the applied N was quite high, 7.1 kg rape seed was increased by application of one kg N forTreatmentT. Nitrogen and phosphorus were the key factors limiting rape yield, and the yield was very lowwhen neither of them was applied. The yield in TreatmentK was significantly lower than that in TYeatmentT, with the former accounting for 77% of the later.展开更多
The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold...The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold plasma ranging from 0-120 W for 15 s.Cold plasma increased the germination,plant growth and yield of oilseed rape,and the treatment of 100 W provided the best result.The germination rate,germination and vigor indices,and uniformity of emergence were improved by cold plasma treatment.Cold plasma raised the relative conductivity and water uptake,and reduced the apparent contact angle.The characteristics of plant growth,including plant height,stem diameter,dry weights of shoot and root at the seedling,bolting and flowering stages were increased by the cold plasma treatment.Yield components,including pod numbers per plant and 1000 seed weights were increased by the cold plasma treatment.Furthermore,the yield per plant increased by 28.20%.These results suggest that cold plasma treatment has the potential to improve the yield of oilseed rape through the enhancement of permeability,wettability and capacity of water uptake of the seeds,seed germination and plant growth.展开更多
Ridge-furrow rainwater harvesting （RFRH） planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in a...Ridge-furrow rainwater harvesting （RFRH） planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas. Supplemental irrigation would still be needed to achieve a higher production. Field experiments were conducted for two growing seasons （2012-2013 and 2013-2014）to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern. Four treatments, including supplemental irrigation amount of 0 （I1）, 60 mm （I2） and 120 mm （I3） with RFRH planting pattern and a control （CK） irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter （ADM）, nitrogen nutrition index （NNI）, radiation use efficiency （RUE）, water use efficiency （WUE）, and seed yield and oil content of the oilseed rape. Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE. However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation. Seed yield was the highest in 13 for both growing seasons. Seed yield and WUE in 13 averaged 3235 kg ha^-1 and 8.85 kg ha^-1 mm-1, respectively. The highest WUE was occurred in 12 for both growing seasons. Seed yield and WUE in 12 averaged 3089 kg ha^-1 and 9.63 kg ha^-1 mm^-1, respectively. Compared to 13, 12 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively. 12 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.展开更多
Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown wint...Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.展开更多
China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesti...China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.展开更多
Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy v...Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.展开更多
长江流域冬油菜主产区一半以上土壤缺镁,影响油菜生长发育和籽粒产量,并可能加剧冻害对油菜的危害。为探究科学施镁肥对提高油菜产量和抗寒性的影响,本研究基于2022/2023和2023/2024年在江西进贤及湖北武穴开展的不同镁肥用量(0、15和45...长江流域冬油菜主产区一半以上土壤缺镁,影响油菜生长发育和籽粒产量,并可能加剧冻害对油菜的危害。为探究科学施镁肥对提高油菜产量和抗寒性的影响,本研究基于2022/2023和2023/2024年在江西进贤及湖北武穴开展的不同镁肥用量(0、15和45kghm^(-2)MgO)的田间试验,以2022/2023年作参考,对比了2023/2024年遭受低温冻害天气后的油菜籽产量及其构成因子、不同部位生物量、镁含量和地上部镁累积量等指标。结果表明,与不施镁肥处理相比,随着镁肥用量的增加,油菜籽产量呈上升趋势(增幅为6.2%~34.9%),同时施用镁肥降低了因低温冻害导致的产量损失(降幅为1.3%~8.9%)。与2022/2023季相比,2023/2024季油菜地上部生物量和镁累积量平均降低了38.0%~47.4%和41.2%~50.6%,施镁肥有效缓解了低温冻害对植株生物量的不利影响(降幅为4.0%~9.4%),同时增加了油菜地上部的镁累积量(增幅为16.9%~46.0%)。施用镁肥主要通过减少低温冻害对直播油菜收获密度和每角粒数的不利影响来提高籽粒产量,而对于移栽油菜而言,则通过有效保证植株的单株角果数来提升油菜产量,从而减轻低温冻害造成的影响。综上,油菜遭受冻害后其产量和镁累积量显著下降,施用镁肥可有效缓解低温冻害的不利影响,且当镁肥用量为45 kg hm^(-2)MgO时,油菜增产及对低温冻害的抵抗效果最佳。展开更多
[目的]为筛选春油菜田防除优势阔叶杂草的高效除草剂。[方法]通过田间试验测定了5种茎叶除草剂对春油菜田阔叶杂草的防除效果及其安全性。[结果]35%氨氯酸·草除灵·二氯吡SC 210 g a.i./hm^(2)除草效果主要表现为对杂草鲜质量...[目的]为筛选春油菜田防除优势阔叶杂草的高效除草剂。[方法]通过田间试验测定了5种茎叶除草剂对春油菜田阔叶杂草的防除效果及其安全性。[结果]35%氨氯酸·草除灵·二氯吡SC 210 g a.i./hm^(2)除草效果主要表现为对杂草鲜质量的抑制,在油菜茎叶使用后40 d对阔叶杂草的防效为80.06%,田间优势杂草密花香薷、藜、猪殃殃的鲜质量防效分别为66.67%、92.71%、76.98%,尤其是对于油菜同属的野油菜具有较好的选择性,鲜质量防效达87.21%,油菜表现安全,增产率达29.92%。试验还发现50%草除灵SC 300 g a.i./hm^(2)处理对藜防效为89.29%,30%二氯吡啶酸AS 180 g a.i./hm^(2)处理对藜、猪殃殃的防效分别为87.50%、80.19%,28.6%氨氯·二氯吡AS处理154.44 g a.i./hm^(2)处理对藜、猪殃殃、野油菜的防效分别为96.73%、88.68%、67.21%。试验中21%氯氨吡啶酸AS110.25 g a.i./hm^(2)处理对田间杂草的防效表现优异,但油菜药害表现重,在试验设计剂量下不宜应用。[结论]35%氨氯酸·草除灵·二氯吡SC与50%草除灵SC、30%二氯吡啶酸AS、28.6%氨氯·二氯吡AS相比,防治效果较好,杀草谱广,并且增产效果明显,可在春油菜田推广使用。而草除灵、二氯吡啶酸、氨氯·二氯吡可根据田间草相选择使用。展开更多
文摘Fate of urea nitrogen (N) applied to rape grown on a red soil was investigated by the ￣(15)N mass balancetechnique, and efficiency of urea and effect of nutrients balance in raising rape yield were investigated ina field plot experiment. One hundred and thirty-eight kg N/ha, 86 kg N/ha as basal dressing and 52 kgN/ha as top dressing, was applied with band application technique. The experiment was conducted in thesoutheast of China, near Yingtan City, Jianxi Province.Results from is￣(15)N mass balance study showed that when urea was applied as basal dressing the plantrecovery was 44.0% of the applied N for Theatment T (with application of N, P, K, B and lime). Plantrecoveries were 38.0%-40.5% for Treatments -K, -B, -lime and +RS (without application of K, B or limeas well as with additional rice straw compared with Theatment T), which were not significantly differentfrom Treatment T. In contrast, plant recovery was only 5.1% for Treatment-P (without application of P),indicating that P was the factor limiting N uptake by rape. However, N remaining in 0-0.30 m soil was highup to 71.6% for Theatment -P, while the corresponding data were 33.0%-42.6% for the other treatments.The total recovery of applied N (including plant recovery and N remaining in 0-0.60 m soil) was 91.5% forTreatment T when urea was applied as basal dressing, while almost all the applied N was recovered when ureawas applied as top dressing. It was suggested that N loss was greatly controlled by using band applicationmethod in this experiment.Results from the field plot experiment showed that N supply capacity of this red soil was very low, andthe efficiency of the applied N was quite high, 7.1 kg rape seed was increased by application of one kg N forTreatmentT. Nitrogen and phosphorus were the key factors limiting rape yield, and the yield was very lowwhen neither of them was applied. The yield in TreatmentK was significantly lower than that in TYeatmentT, with the former accounting for 77% of the later.
基金supported by the National Key Research and Development Program of China(Nos.2016YFD0200305,2017YFD0200604)the Knowledge Innovation Program of the Institute of Soil Science,the Chinese Academy of Sciences(No.ISSASIP1634)+2 种基金the Jiangsu Provincial Public Institutions Program for Research Conditions and Building Capacity(No.BM2015019)the Foundation of Jiangsu Key Laboratory for the Research and Utilization of Plant Resources(No.JSPKLB201606)the Suzhou Xiangcheng District Science and Technology Project(No.201703)
文摘The effects of low-vacuum helium cold plasma treatment on the seed germination,plant growth and yield of oilseed rape（Brassica napus L.cv.Zhongshuang 9） were investigated.Seeds were exposed to low-vacuum helium cold plasma ranging from 0-120 W for 15 s.Cold plasma increased the germination,plant growth and yield of oilseed rape,and the treatment of 100 W provided the best result.The germination rate,germination and vigor indices,and uniformity of emergence were improved by cold plasma treatment.Cold plasma raised the relative conductivity and water uptake,and reduced the apparent contact angle.The characteristics of plant growth,including plant height,stem diameter,dry weights of shoot and root at the seedling,bolting and flowering stages were increased by the cold plasma treatment.Yield components,including pod numbers per plant and 1000 seed weights were increased by the cold plasma treatment.Furthermore,the yield per plant increased by 28.20%.These results suggest that cold plasma treatment has the potential to improve the yield of oilseed rape through the enhancement of permeability,wettability and capacity of water uptake of the seeds,seed germination and plant growth.
基金supported by the Special Fund for Agro-scientific Research in the Public Interest,China(201503105 and 201503125)the National High-Tech R&D Program of China(863 Program,2011AA100504)
文摘Ridge-furrow rainwater harvesting （RFRH） planting pattern can lessen the effect of water deficits throughout all crop growth stages, but water shortage would remain unavoidable during some stages of crop growth in arid and semiarid areas. Supplemental irrigation would still be needed to achieve a higher production. Field experiments were conducted for two growing seasons （2012-2013 and 2013-2014）to determine an appropriate amount of supplemental irrigation to be applied to winter oilseed rape at the stem-elongation stage with RFRH planting pattern. Four treatments, including supplemental irrigation amount of 0 （I1）, 60 mm （I2） and 120 mm （I3） with RFRH planting pattern and a control （CK） irrigated with 120 mm with flat planting pattern, were set up to evaluate the effects of supplemental irrigation on aboveground dry matter （ADM）, nitrogen nutrition index （NNI）, radiation use efficiency （RUE）, water use efficiency （WUE）, and seed yield and oil content of the oilseed rape. Results showed that supplemental irrigation improved NNI, RUE, seed yield and oil content, and WUE. However, the NNI, RUE, seed yield and oil content, and WUE did not increase significantly or even showed a downward trend with excessive irrigation. Seed yield was the highest in 13 for both growing seasons. Seed yield and WUE in 13 averaged 3235 kg ha^-1 and 8.85 kg ha^-1 mm-1, respectively. The highest WUE was occurred in 12 for both growing seasons. Seed yield and WUE in 12 averaged 3089 kg ha^-1 and 9.63 kg ha^-1 mm^-1, respectively. Compared to 13, 12 used 60 mm less irrigation amount, had an 8.9% higher WUE, but only 4.5 and 0.4% lower seed yield and oil content, respectively. 12 saved water without substantially sacrificing yield or oil content, so it is recommended as an appropriate cultivation and irrigation schedule for winter oilseed rape at the stem-elongation stage.
基金supported by the National Key Technologies R&D Program of China during the 11th Five-Year Plan period (2010BAD01B05)the Earmarked Fund for China Agriculture Research System (CARS-13)+1 种基金the Program for Changjiang Scholars and Innovative Research Team in University of China (IRT1247)the Fundamental Research Funds for the Central Universities,China (2013PY113)
文摘Direct-sowing establishment method has great significance in improving winter oilseed rape（Brassica napus L.） production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape（DOR） performance and population development dynamic are still not well understood. Therefore, five on-farm experiments were conducted in the reaches of the Yangtze River（RYR） to determine the effects of nitrogen（N）, phosphorus（P）, and potassium（K） deficiencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment（NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1） and three nutrient deficiency treatments based on the NPK treatment, i.e., –N, –P, and –K. The results indicated that DOR population density declined gradually throughout the growing season, especially at over-wintering and pod-development stages. Nutrient deficiency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deficiency treatment. Averaged across all the experiments, seed yield reduced 61% by N deficiency, 38.3% by P deficiency, and 14.4% by K deficiency. The negative effects of nutrient deficiency on DOR performances followed the order of –N–P–K, and the effects were various among different nutrient deficiencies. Although N deficiency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deficiency significantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deficiency mainly decreased individual growth and yield, but did not affect density dynamic. Our results highlighted the importance of balanced NPK application in DOR production, suggesting that management strategy of these nutrients should be comprehensively considered with an aim to build an appropriate population structure with balanced plant density and individual growth.
基金financial support provided by the National Key Research and Development Program of China (2016YFD0702100)the Special Funds for the Construction of Modern Agricultural Industrial Technology System (CARS-13)
文摘China is one of the major rapeseed production countries in the world,but harvesting mechanization was still backward,and high harvest loss was a key inhibiting factor for rapeseed production.To obtain optimum harvesting date for winter rape in the Yangtze River Valley of China,artificial simulated combine harvesting and artificial two-stage harvesting were adopted to find correlations between harvesting date,rape variety,seed oil content,protein content,grain moisture rate,rapeseed straw moisture content,rapeseed unthreshing rate,grain drop loss rate,thousand seeds weight(TSW),and harvesting economic coefficient(HEC).Analysis of variance showed that rapeseed oil content,protein content and TSW were correlated with rape variety;HEC was correlated with harvesting method and rape variety.Rape variety was the dominant factor of rapeseed oil content,protein content,TSW and HEC.Grain moisture rate,un-threshing rate,grain drop loss rate and straw moisture content were correlated with harvesting method and date.Harvesting date was the dominant factor of rapeseed moisture rate,un-threshing rate,grain drop loss rate and straw moisture rate.Single factor tests further proved that harvesting date had less impact on rapeseed oil content,protein content,TSW and HEC.It showed little correlation with rapeseed quality except grain moisture rate.The optimum harvesting date could be known by change in straw moisture content.The combined harvesting should be carried out during the grain moisture content of 15%-20%with TSW stabilized in the highest level.The twostage harvesting cutting should be carried out at the grain moisture content of 35%-40%.This research offered a reference to harvesting method and date for rape cultivated in the Yangtze River Valley.
基金Project supported by Items of Institution of Higher Education Scientific Research of Hebei Province(ZD20131020)Hebei Vegetable Innovation Projects of Modern Agricultural Industry Technology System and Academy of Agricultural Sciences of Qinhuangdao City
文摘Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.
文摘长江流域冬油菜主产区一半以上土壤缺镁,影响油菜生长发育和籽粒产量,并可能加剧冻害对油菜的危害。为探究科学施镁肥对提高油菜产量和抗寒性的影响,本研究基于2022/2023和2023/2024年在江西进贤及湖北武穴开展的不同镁肥用量(0、15和45kghm^(-2)MgO)的田间试验,以2022/2023年作参考,对比了2023/2024年遭受低温冻害天气后的油菜籽产量及其构成因子、不同部位生物量、镁含量和地上部镁累积量等指标。结果表明,与不施镁肥处理相比,随着镁肥用量的增加,油菜籽产量呈上升趋势(增幅为6.2%~34.9%),同时施用镁肥降低了因低温冻害导致的产量损失(降幅为1.3%~8.9%)。与2022/2023季相比,2023/2024季油菜地上部生物量和镁累积量平均降低了38.0%~47.4%和41.2%~50.6%,施镁肥有效缓解了低温冻害对植株生物量的不利影响(降幅为4.0%~9.4%),同时增加了油菜地上部的镁累积量(增幅为16.9%~46.0%)。施用镁肥主要通过减少低温冻害对直播油菜收获密度和每角粒数的不利影响来提高籽粒产量,而对于移栽油菜而言,则通过有效保证植株的单株角果数来提升油菜产量,从而减轻低温冻害造成的影响。综上,油菜遭受冻害后其产量和镁累积量显著下降,施用镁肥可有效缓解低温冻害的不利影响,且当镁肥用量为45 kg hm^(-2)MgO时,油菜增产及对低温冻害的抵抗效果最佳。
文摘[目的]为筛选春油菜田防除优势阔叶杂草的高效除草剂。[方法]通过田间试验测定了5种茎叶除草剂对春油菜田阔叶杂草的防除效果及其安全性。[结果]35%氨氯酸·草除灵·二氯吡SC 210 g a.i./hm^(2)除草效果主要表现为对杂草鲜质量的抑制,在油菜茎叶使用后40 d对阔叶杂草的防效为80.06%,田间优势杂草密花香薷、藜、猪殃殃的鲜质量防效分别为66.67%、92.71%、76.98%,尤其是对于油菜同属的野油菜具有较好的选择性,鲜质量防效达87.21%,油菜表现安全,增产率达29.92%。试验还发现50%草除灵SC 300 g a.i./hm^(2)处理对藜防效为89.29%,30%二氯吡啶酸AS 180 g a.i./hm^(2)处理对藜、猪殃殃的防效分别为87.50%、80.19%,28.6%氨氯·二氯吡AS处理154.44 g a.i./hm^(2)处理对藜、猪殃殃、野油菜的防效分别为96.73%、88.68%、67.21%。试验中21%氯氨吡啶酸AS110.25 g a.i./hm^(2)处理对田间杂草的防效表现优异,但油菜药害表现重,在试验设计剂量下不宜应用。[结论]35%氨氯酸·草除灵·二氯吡SC与50%草除灵SC、30%二氯吡啶酸AS、28.6%氨氯·二氯吡AS相比,防治效果较好,杀草谱广,并且增产效果明显,可在春油菜田推广使用。而草除灵、二氯吡啶酸、氨氯·二氯吡可根据田间草相选择使用。
