黏虫蜜源植物花蜜中游离氨基酸的测定与分析

为探讨黏虫成虫与迁飞中转地蜜源植物的营养关系,利用氨基酸分析仪测定了其蜜源植物油菜和紫云英花蜜中游离氨基酸的种类和含量。结果显示,油菜和紫云英花蜜中都含17种氨基酸,油菜花蜜中游离氨基酸的总含量是紫云英花蜜的2.47倍。紫云英花蜜与油菜花蜜中各游离氨基酸的含量不同。油菜花蜜中除胱氨酸、蛋氨酸、苯丙氨酸、赖氨酸、精氨酸外,其他游离氨基酸的含量均比紫云英花蜜中相应的氨基酸高,其中丙氨酸、酪氨酸、丝氨酸、甘氨酸、天冬氨酸的含量分别是紫云英花蜜的14.36倍、11.35倍、5.70倍、4.69倍、4.11倍。研究还发现,紫云英蜂蜜中氨基酸总量是紫云英花蜜中氨基酸总量的4.29倍,油菜花蜜比油菜蜂蜜多含了胱氨酸和亮氨酸。因此,不能用油菜蜂蜜、紫云英蜂蜜代替油菜花蜜、紫云英花蜜来研究紫云英和油菜花蜜对黏虫的营养效应。     

紫云英不同还田量的效果研究

采用田间小区试验,研究紫云英鲜草还田对水稻产量和经济效益的影响,结果表明:每667 m2翻压紫云英1 500～2 000 kg能促进早稻的生长发育,增加产量,提高经济效益;同时还能提高土壤速效养分含量,改良土壤,培肥地力。     

紫云英与化肥配施对水稻生长和土壤养分含量的影响

2009年在河南省信阳市农业科学研究所进行了紫云英(Astragaius sinicus L.)与化肥配施对水稻生长(Oryza sativa L.)和土壤养分含量影响试验。结果表明:紫云英和化肥配施可促进水稻生长,增加水稻产量,增加土壤有机质含量,提高土壤速效氮、磷、钾含量。其中,80%化肥的4个处理水稻的总产量为37205.63kg·hm-2,60%化肥的4个处理水稻的总产量为37395.01kg·hm-2。从紫云英翻压量来看,15000kg·hm-2的2个处理水稻总产量为19297.901kg·hm-2,22500kg·hm-2的2个处理水稻总产量为18956.25kg·hm-2,30000kg·hm-2的2个处理水稻总产量为17718.76kg·hm-2,37500kg·hm-2的2个处理水稻总产量为18628.13kg·hm-2。总的来看,化肥量60%和紫云英翻压量15000kg·hm-2、22500kg·hm-2配施比较适宜。     

Two perennial legumes (Astragalus adsurgens Pall. and Lespedeza davurica S.) adapted to semiarid environments are not as productive as lucerne (Medicago sativa L.), but use less water

Perennial forage legumes, particularly lucerne (Medicago sativa L.), play a significant role in crop/livestock mixed farming systems in the semiarid region of the Loess Plateau of China as stock feed and a source of nitrogen for subsequent crops. However, there is evidence that lucerne reduces soil water deep in the soil profile, thereby reducing subsequent crop productivity. From 2004 to 2010, this study evaluated the forage productivity and water use of two locally adapted perennial legume species, milk vetch (Astragalus adsurgens Pall.) and bush clover (Lespedeza davurica S.), compared with lucerne. The 7‐year total and average annual forage yield of milk vetch were 56 and 8 t ha^?1 and bush clover was 42 and 6 t ha^?1, respectively, significantly lower than lucerne at 91 and 13 t ha^?1. However, despite lower water‐use efficiencies (16 and 12 kg ha^?1 mm^?1 for milk vetch and bush clover, respectively, compared to 22 kg ha^?1 mm^?1 for lucerne), the total 7‐year water use in milk vetch and bush clover was 3500 mm and 3490 mm, respectively, which was 135–140 mm less than lucerne. After 7 years, lucerne had extracted water from the upper 5 m soil, whereas bush clover used water mainly from the upper 2 m of the soil profile and milk vetch still had some water available below 3 m. We conclude that while the locally adapted forage legumes were not as productive as lucerne as a source of fodder in mixed cropping/livestock system in this region, they use less water, which may be advantageous in drier regions.     

混播比例和刈割茬次对多花黑麦草+箭筈豌豆混播草地土壤细菌群落的影响

为探讨混播比例和刈割茬次对一年生禾豆混播草地土壤细菌群落的影响,本研究设多花黑麦草（Lolium multiflorum Lamk.）100%（R₁）、75%多花黑麦草+25%箭筈豌豆（Vicia sativa L.）（R₂）、50%多花黑麦草+50%箭筈豌豆（R₃）、25%多花黑麦草+75%箭筈豌豆（R₄）与100%箭筈豌豆（R₅）5个处理,分别于2017年1月4日（H₁）、3月14日（H₂）、4月21日（H₃）和5月19日（H₄）4个时期刈割,并采集0~20 cm土壤样本,分析土壤细菌群落组成。结果表明,变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、厚壁菌门（Firmicutes）、拟杆菌门（Bacteroidetes）、酸杆菌门（Acidobacteria）、芽单胞菌门（Gemmatimonadetes）、硝化螺旋菌门（Nitrospirae）、浮霉菌门（Planctomycetes）、绿弯菌门（Chloroflexi）和疣微菌门（Verrucomicrobia）是混播草地主要土壤细菌群落。禾豆混播比例对土壤alpha多样性无显著性影响,刈割茬次对土壤细菌操作分类单元（Operational Taxonomic Unit,OTU）和物种丰富度指标（Chao 1指数）影响效果显著（P<0.05）,改变了细菌群落结构。刈割茬次引起土壤细菌群落变化,影响了多花黑麦草和箭筈豌豆混播草地土壤细菌群落结构的均匀性。     

Substitution of chemical fertilizer by Chinese milk vetch improves the sustainability of yield and accumulation of soil organic carbon in a double-rice cropping system

The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon(SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch(Mv). We conducted a 10-year(2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application(22.5 Mg ha~(–1)). Fertilizer and Mv were applied both individually and in combination(sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80(by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index(SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input(22.5 Mg ha~(–1)), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate(with the value higher by 71.6 and 70.1%),whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers(e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.     

高寒牧区黑麦和箭筈豌豆混播对草产量和营养品质的影响研究

为筛选适宜甘肃高寒牧区的箭筈豌豆与黑麦混播组合及比例，采用裂区设计，研究了3个箭筈豌豆品种（绿箭1号、绿箭2号和绿箭431）与黑麦新品系C33在不同混播比例（0∶100、20∶80、30∶70、40∶60、50∶50、60∶40、70∶30、80∶20、100∶0）下的生产性能及营养品质。结果表明，从混播组合看，A?（C33×绿箭1号）的平均干草产量（7.16 t·hm^-2）和综合评价值（0.860）较高；从混播比例看，B?（60∶40）的平均干草产量（8.01 t·hm^-2）和综合评价值（0.691）最高；混播组合和混播比例间的交互作用表明，A?以B?比例混播时干草产量（9.03 t·hm^-2）和综合评价值（0.711）最高。     

一年生混播人工草地生物量、品质及种间竞争的动态研究

作者在华北农牧交错带对燕麦和箭管豌豆单播及混播的一年生人工草地进行了生物量、品质及种间竞争的动态研究。结果表明：整个的生育期除蜡熟期、成熟期外,燕麦单据的产草量一直高于其它处理的产草量,燕麦50％ 箭管豌豆50％处理在蜡熟期、成熟期产草量表现最高;从开花期开始,各处理的单位面积粗蛋白质产量均显著（P＜0.05）高于燕麦单播的产量．而DNF、ADF含量又低于燕麦单播的含量;燕麦蜡熟期和箭管豌豆结荚期是牧草最佳的刈割期,以燕麦25％ 箭管豌豆75％和燕麦50％ 箭管豌豆50％混播比例为最好;从整个混播群落看,燕麦的干物质积累速率快,植株高,其竞争力超过箭管豌豆,箭管豌豆一直处于劣势地位。     

箭筈豌豆、玉米产量对间作和施氮水平的响应

研究不同施氮水平下箭筈豌豆、玉米产量对单作和间作的响应,对于优化栽培措施、提高作物产量具有重要意义。本试验于2017年在甘肃河西绿洲灌溉区进行,重点研究是不同施氮水平下箭筈豌豆、玉米在单作及间作模式中干物质累积、产量构成、产量表现。结果表明,间作箭筈豌豆干物质累积量与单作相比在不施氮(N0)、减量施氮(N1)和常规施氮(N2)处理下分别提高44.0%、36.7%和37.2%;施氮水平间,间作模式下N1比N2和N0提高9.1%和25.5%,单作模式下提高9.4%和32.1%。间作玉米干物质累积量与单作相比在N0、N1和N2处理下分别提高23.3%、22.5%和23.0%;施氮水平间,间作模式下N1比N2和N0提高9.3%和19.8%,单作模式下提高9.9%和20.7%。间作模式下箭筈豌豆豆荚数和玉米穗数较相应单作分别增加7.6%和14.5%,两者的产量较单作分别提高34.9%和27.0%。由通径分析可知,箭筈豌豆产量决定次序是豆荚数>粒重>单荚粒数,玉米产量决定次序是穗数>粒重>穗粒数。间作结合施氮量240 kg/hm²能获得较高干物质积累量和产量,是河西灌溉区玉米间作箭筈豌豆适宜的施氮水平。     

紫云英施用量对土壤活性有机碳和碳转化酶活性的影响

利用紫云英还田的定位试验研究不同紫云英施用量下土壤活性有机碳含量和碳转化酶活性的变化。试验包括对照、施用化肥和4个紫云英施用量(30、60、90和120 t·hm~(-2))处理。结果表明:与对照相比,施用化肥和紫云英均能够显著增加土壤活性有机碳(可溶性有机碳、热水提取态有机碳、微生物生物量碳和颗粒有机碳)含量,并且随着紫云英施用量的增加土壤活性有机碳含量显著增加。土壤碳转化酶活性的变化规律与土壤活性有机碳相同,其中施用化肥和紫云英较对照处理分别提高14%和24%~55%的纤维素酶活性、27%和45%~187%的蔗糖酶活性、42%和51%~165%的β-葡萄糖苷酶活性、11%和11%~24%的酚氧化酶活性以及16%和16%~27%的过氧化物酶活性。与对照相比,施用化肥对相对酶活性(酶活性与微生物生物量碳的比值)无显著影响;增加紫云英施用量能够显著增加相对蔗糖酶和相对β-葡萄糖苷酶活性,降低相对酚氧化酶活性和相对过氧化物酶活性。逐步回归分析表明土壤活性有机碳组分含量主要受纤维素酶、β-葡萄糖苷酶和酚氧化酶活性的影响。