The aim of this study was to identify the main classes of secondary metabolites present in the root and shoot crude extracts and fractions from the forage grass Urochloa humidicola (Rendle) Morrone & Zuloaga and t...The aim of this study was to identify the main classes of secondary metabolites present in the root and shoot crude extracts and fractions from the forage grass Urochloa humidicola (Rendle) Morrone & Zuloaga and to evaluate the allelopathic effect of these metabolites on forage legumes for intercropping. Phytochemical prospecting analyses, 1H NMR and capillary electrophoresis were performed on extracts of U. humidicola. Allelopathic activity was evaluated in germination of Stylosanthes, Macrotyloma axillare and Lactuca sativa L. (standard) in the presence of crude extracts, isolated saponins, flavonoids and trans-cinnamic acid. The metabolite classes present in the extracts could be determined by the combined use of the tested analytical techniques, but their use alone was usually not sufficient to chemically characterize the species. Capillary electrophoresis was effective in detecting phenolic compounds. Macrotyloma axillare was tolerant to crude extracts of U. humidicola. Saponins and trans-cinnamic acid, but not the flavonoids, reduced germination of the target plants.展开更多
[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] ...[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] Effects of such two influencing factors as line spacing and seedling density on the leaf-stem ratio, DW/FW ratio and grass yield of forage sweet sorghum were analyzed by using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statis- tics. v22 stati, stics software. [ Results ~ Seedling density and line spacing had no obvious effect on the leaf-stem ratio and DW/FW ratio of forage sweet sorghum but had obvious influences on the grass yield. Moreover, the optimal combination of seedling density and line spacing for high yield of forage sweet sorghum was A2 B4, that is, seedling density was 225 000 plants/hm2, and line spacing was 40 cm. [ Conclusions] The results provided a theoretical basis and technical support for high-yield cultivation techniques of forage sweet sorghum.展开更多
This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The ...This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The study was performed by using randomized block design(RBD)with eight treatments(S0:no introduction,S1:Cynodon dactilon,S2:Dicanthium aristatum,S3:C.plectotachyus,S4:Brachiaria decumbens,S5:Desmanthus virgatus,S6:Macroptilium atropurpureum,S7:Clitoria ternatea)with four replications.Procedures on this study include trial plots preparation,tillers preparation for each species,introduction of species in trial plots,maintenance and observation of the productivity.Variables observed were forage production(fresh and dry matter(DM)in ton/ha),nutrient content(%)and stock capacity(animal unit(AU)/ha).Data were analyzed for variance based on RBD and followed by Duncan’s test.Analysis of variance showed that introduction of species had a very significant effect(p<0.01)on all observed variables.The introduction of M.atropurpureum produced the highest fresh forage(2.1 t/ha)and DM production(0.69 t/ha).M.atropurpureum also had the highest DM content(43.61%),nitrogen free extract(52.52%)and stock capacity(1.06 AU/ha).The highest crude protein and crude fiber content were found in D.virgatus(4.31%and 36.62%).The highest extract ether was observed in D.aristatum(1.48%).No introduction had the lowest productivity,but demonstrated the highest ash content.The introduction of palatable species increased the productivity of native pasture in Timor and M.atropupureum was the best introduced species.展开更多
针对目前牧草收获、粉碎加工设备输送和切割等机构研究过程中离散元仿真缺乏准确模型的问题,以含水率高、物理力学特性较为复杂的苜蓿现蕾期茎秆为研究对象,借助EDEM仿真软件,分别基于Hertz-Mindlin(no slip)和Hertz-Mindlin with bond...针对目前牧草收获、粉碎加工设备输送和切割等机构研究过程中离散元仿真缺乏准确模型的问题,以含水率高、物理力学特性较为复杂的苜蓿现蕾期茎秆为研究对象,借助EDEM仿真软件,分别基于Hertz-Mindlin(no slip)和Hertz-Mindlin with bonding接触模型对物理参数和粘结参数进行标定。以休止角和剪切试验为基础,通过Plackett-Burman试验、Steepest ascent试验和Box-Behnken试验确定了苜蓿茎秆的泊松比、剪切模量、碰撞恢复系数、静摩擦因数、滚动摩擦因数等物理参数和法向接触刚度、切向接触刚度、临界法向应力、临界切向应力、粘结半径等粘结参数。以确定的物理参数进行休止角仿真试验,结果表明,仿真休止角与物理试验休止角相对误差为0.52%;以确定的粘结参数进行剪切仿真试验,结果表明,仿真剪切破坏力与物理试验仿真破坏力相对误差为0.86%,说明所标定的参数能够真实反映苜蓿现蕾期茎秆的物理和力学特性。展开更多
刈割和施肥是豆禾混播草地生产过程中极为重要的田间管理措施,合理的留茬高度和氮磷配施模式可以有效提高混播草地的生产性能。为探究不同留茬高度和施肥模式对多年生豆禾混播草地产量与品质的影响,在河西走廊地区以紫花苜蓿、无芒雀麦...刈割和施肥是豆禾混播草地生产过程中极为重要的田间管理措施,合理的留茬高度和氮磷配施模式可以有效提高混播草地的生产性能。为探究不同留茬高度和施肥模式对多年生豆禾混播草地产量与品质的影响,在河西走廊地区以紫花苜蓿、无芒雀麦和长穗偃麦草1∶1∶1建植的第3年豆禾混播草地为试验对象,利用裂区试验设计,以留茬高度为主区,设置5 cm(A_(1))、8 cm(A_(2))、11 cm(A_(3))3个留茬高度,施肥模式为副区,设置不施肥CK(B_(1))、单施磷肥:150 kg P_(2)O_(5)·hm^(-2)(B_(2))、低氮高磷:75 kg N·hm^(-2)+225 kg P_(2)O_(5)·hm^(-2)(B_(3))、氮磷平衡:150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)(B_(4))、单施氮肥:150 kg N·hm^(-2)(B_5)、高氮低磷:225 kg N·hm^(-2)+75 kg P_(2)O_(5)·hm^(-2)(B_(6))6个施肥模式,在混播草地中豆科牧草初花期进行刈割,施肥方式为第1茬刈割后追施。结果表明:以A_(3)B_(3)(11 cm留茬高度和75 kg N·hm^(-2)+225 kg P_(2)O_(5)·hm^(-2)的施肥模式)处理组合全年产量最高(19626 kg·hm^(-2));A_(2)B_(2)(8 cm留茬高度和150 kg P_(2)O_(5)·hm^(-2)的施肥模式)处理组合全年产量最低(14342 kg·hm^(-2))。提高留茬高度会在一定程度上降低紫花苜蓿整体品质,提高禾本科牧草整体品质。增施氮肥的同时减施磷肥可有效提高牧草粗蛋白含量和相对饲用价值(RFV),施用量过高会使牧草粗蛋白含量和相对饲用价值下降,最合理的氮磷配施模式为150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)。综合产量和品质的结果来看,适当的磷肥施用量可以显著提高牧草营养品质。利用TOPSIS综合评价模型对混播草地产量及各混播组分营养品质进行整体评价后得出:8 cm的留茬高度以及施150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)的氮磷为适宜在河西走廊地区紫花苜蓿+无芒雀麦+长穗偃麦草混播草地利用的留茬高度与施肥模式的组合。展开更多
文摘The aim of this study was to identify the main classes of secondary metabolites present in the root and shoot crude extracts and fractions from the forage grass Urochloa humidicola (Rendle) Morrone & Zuloaga and to evaluate the allelopathic effect of these metabolites on forage legumes for intercropping. Phytochemical prospecting analyses, 1H NMR and capillary electrophoresis were performed on extracts of U. humidicola. Allelopathic activity was evaluated in germination of Stylosanthes, Macrotyloma axillare and Lactuca sativa L. (standard) in the presence of crude extracts, isolated saponins, flavonoids and trans-cinnamic acid. The metabolite classes present in the extracts could be determined by the combined use of the tested analytical techniques, but their use alone was usually not sufficient to chemically characterize the species. Capillary electrophoresis was effective in detecting phenolic compounds. Macrotyloma axillare was tolerant to crude extracts of U. humidicola. Saponins and trans-cinnamic acid, but not the flavonoids, reduced germination of the target plants.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(20120304201)
文摘[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] Effects of such two influencing factors as line spacing and seedling density on the leaf-stem ratio, DW/FW ratio and grass yield of forage sweet sorghum were analyzed by using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statis- tics. v22 stati, stics software. [ Results ~ Seedling density and line spacing had no obvious effect on the leaf-stem ratio and DW/FW ratio of forage sweet sorghum but had obvious influences on the grass yield. Moreover, the optimal combination of seedling density and line spacing for high yield of forage sweet sorghum was A2 B4, that is, seedling density was 225 000 plants/hm2, and line spacing was 40 cm. [ Conclusions] The results provided a theoretical basis and technical support for high-yield cultivation techniques of forage sweet sorghum.
文摘This research was aimed to evaluate the productivity of native pasture in Timor Island by introducing various palatable species.The study was carried out on native pasture in Tuatuka,Timor Island for seven months.The study was performed by using randomized block design(RBD)with eight treatments(S0:no introduction,S1:Cynodon dactilon,S2:Dicanthium aristatum,S3:C.plectotachyus,S4:Brachiaria decumbens,S5:Desmanthus virgatus,S6:Macroptilium atropurpureum,S7:Clitoria ternatea)with four replications.Procedures on this study include trial plots preparation,tillers preparation for each species,introduction of species in trial plots,maintenance and observation of the productivity.Variables observed were forage production(fresh and dry matter(DM)in ton/ha),nutrient content(%)and stock capacity(animal unit(AU)/ha).Data were analyzed for variance based on RBD and followed by Duncan’s test.Analysis of variance showed that introduction of species had a very significant effect(p<0.01)on all observed variables.The introduction of M.atropurpureum produced the highest fresh forage(2.1 t/ha)and DM production(0.69 t/ha).M.atropurpureum also had the highest DM content(43.61%),nitrogen free extract(52.52%)and stock capacity(1.06 AU/ha).The highest crude protein and crude fiber content were found in D.virgatus(4.31%and 36.62%).The highest extract ether was observed in D.aristatum(1.48%).No introduction had the lowest productivity,but demonstrated the highest ash content.The introduction of palatable species increased the productivity of native pasture in Timor and M.atropupureum was the best introduced species.
文摘针对目前牧草收获、粉碎加工设备输送和切割等机构研究过程中离散元仿真缺乏准确模型的问题,以含水率高、物理力学特性较为复杂的苜蓿现蕾期茎秆为研究对象,借助EDEM仿真软件,分别基于Hertz-Mindlin(no slip)和Hertz-Mindlin with bonding接触模型对物理参数和粘结参数进行标定。以休止角和剪切试验为基础,通过Plackett-Burman试验、Steepest ascent试验和Box-Behnken试验确定了苜蓿茎秆的泊松比、剪切模量、碰撞恢复系数、静摩擦因数、滚动摩擦因数等物理参数和法向接触刚度、切向接触刚度、临界法向应力、临界切向应力、粘结半径等粘结参数。以确定的物理参数进行休止角仿真试验,结果表明,仿真休止角与物理试验休止角相对误差为0.52%;以确定的粘结参数进行剪切仿真试验,结果表明,仿真剪切破坏力与物理试验仿真破坏力相对误差为0.86%,说明所标定的参数能够真实反映苜蓿现蕾期茎秆的物理和力学特性。
文摘刈割和施肥是豆禾混播草地生产过程中极为重要的田间管理措施,合理的留茬高度和氮磷配施模式可以有效提高混播草地的生产性能。为探究不同留茬高度和施肥模式对多年生豆禾混播草地产量与品质的影响,在河西走廊地区以紫花苜蓿、无芒雀麦和长穗偃麦草1∶1∶1建植的第3年豆禾混播草地为试验对象,利用裂区试验设计,以留茬高度为主区,设置5 cm(A_(1))、8 cm(A_(2))、11 cm(A_(3))3个留茬高度,施肥模式为副区,设置不施肥CK(B_(1))、单施磷肥:150 kg P_(2)O_(5)·hm^(-2)(B_(2))、低氮高磷:75 kg N·hm^(-2)+225 kg P_(2)O_(5)·hm^(-2)(B_(3))、氮磷平衡:150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)(B_(4))、单施氮肥:150 kg N·hm^(-2)(B_5)、高氮低磷:225 kg N·hm^(-2)+75 kg P_(2)O_(5)·hm^(-2)(B_(6))6个施肥模式,在混播草地中豆科牧草初花期进行刈割,施肥方式为第1茬刈割后追施。结果表明:以A_(3)B_(3)(11 cm留茬高度和75 kg N·hm^(-2)+225 kg P_(2)O_(5)·hm^(-2)的施肥模式)处理组合全年产量最高(19626 kg·hm^(-2));A_(2)B_(2)(8 cm留茬高度和150 kg P_(2)O_(5)·hm^(-2)的施肥模式)处理组合全年产量最低(14342 kg·hm^(-2))。提高留茬高度会在一定程度上降低紫花苜蓿整体品质,提高禾本科牧草整体品质。增施氮肥的同时减施磷肥可有效提高牧草粗蛋白含量和相对饲用价值(RFV),施用量过高会使牧草粗蛋白含量和相对饲用价值下降,最合理的氮磷配施模式为150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)。综合产量和品质的结果来看,适当的磷肥施用量可以显著提高牧草营养品质。利用TOPSIS综合评价模型对混播草地产量及各混播组分营养品质进行整体评价后得出:8 cm的留茬高度以及施150 kg N·hm^(-2)+150 kg P_(2)O_(5)·hm^(-2)的氮磷为适宜在河西走廊地区紫花苜蓿+无芒雀麦+长穗偃麦草混播草地利用的留茬高度与施肥模式的组合。
