Effect of Nitrogen Rate and Stubble Height on Dry Matter Yield,Crude Protein Content and Crude Protein Yield of a Sorghum–Sudangrass Hybrid[Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf.] in the Three‐Cutting System

In this study, the effects of nitrogen (N) rate (60, 120, 180 and 240 kg N ha^?1 applied in three equal dressings at seeding and after the first and second cuttings) and stubble height (7, 14 and 21 cm) on the dry matter (DM) yield, crude protein (CP) content, and CP yield of a sorghum–sudangrass hybrid [Sorghum bicolor (L.) Moench × Sorghum sudanense (Piper) Stapf., cv. Pioneer 988] in the three‐cut system was investigated. The N rate had no significant effect in the first and third cuttings, but in the second cutting DM yields increased significantly with increase in N rate. The highest yield of 9.1 t ha^?1 was obtained with 80 kg N ha^?1 for the average of 2 years at the second cutting, but no significant difference was found among the 40, 60 and 80 kg N ha^?1 rates. CP content and yield were not significantly affected by N rate at the first and third cuttings, but CP content and yield were significantly affected by application of N at the second cutting. Stubble height had a significant effect on CP content at the third cutting. However, it had no significant effect on CP content at the first and second cuttings. Stubble height had a significant effect on the CP yield at the first cutting, but no significant effect on CP yield at the second and third cuttings.     

不同类型日粮饲喂幼龄山羊的效果研究

在精料用量相同、定量采食的条件下,研究不同粗料配合、不同加工方法对幼龄波尔羊生产性能的影响,并分析其经济效益。结果表明:粗料为35%稻秆粉、15%砻糠的 号全混合颗粒料在本次试验中的效果最为突出。与粗料为青草的日粮1相比,试羊日增重、饲料转化率分别提高48.4%(P<0.05)和27.9%,且每千克增重饲料费用降低41.5%;与粗料为稻秸散料的日粮2相比,试羊日增重、饲料转化率分别提高了53.3%(P<0.05)和26.9%,且每千克增重饲料费用降低30.9%。经济效益明显。     

几种优良人工牧草矿质元素含量的比较研究

就地上部而言,在3种豆科牧草中,白三叶以N、P、K、Fe、Co、Na含量较高,红三叶以Mg、Zn含量较高。在3种禾本科牧草中,鸭茅以P、K、Mg、Mn、Cu、Zn、Mo含量较高,草地早熟禾以Fe较高。3种豆科牧草N、Ca、Mg、V、Sr的平均含量显著高于禾本科牧草。地上部与地下部比较,豆科牧草的P、K、Ca、Mn、Zn、Na含量前者显著高于后者;禾本科牧草的N、P、K、B含量,前者明显高于后者。     

新疆森工技术进步贡献份额的测算

新疆森工企业是新疆林业的重要组成部分。森工技术进步率是全面考核林业综合水平的重要指标之一。本文根据新疆森工统计资料，首次采用增长速度方程、综合要素生产率指数、总因子生产率指数三种模型测算了新疆森工技术进步贡献份额（１９８１年到１９８６年）。结果表明，新疆森工年均技术进步率在０．５％～０．５２２％之间，技术进步对森工总产值增长的贡献份额在３４％～３６％之间。     

三种幼虫外寄生蜂蛋白酶含量与离体培养饲料的关系

在离体培养幼虫外寄生蜂过程中，发现不同的蜂对饲料中的蛋白质及游离氨基酸的含量有不同的要求，本文对麦蛾茧蜂（Ｂ．ｈｅｂｅｔｏｒ），矛茧蜂（Ｏ．Ｐｌａｌｉａｔｕｓ），管氏肿腿蜂（Ｓ．ｇｕａｎｉ）的蛋白酶活性，饲料中蛋白质及游离氨基酸含量进行了测定．实验表明：蛋白酶含量低的蜂，饲料中含高游离氨基酸及低蛋白；蛋白酶含量高的蜂，饲料中含低游离氨基酸及高蛋白。     

不同喂养条件和营养强化对大型Sou总脂及脂肪酸组成的影响

大型Sou的总脂和脂肪酸组成随食物的变化及营养强化的实施而发生显著变化。酵母组总脂为2．5％，明显高于海水小球藻组（1．65％）和有机肥组（1．5％）。经鱼油强化或海水小球藻二次培养后脂类含量明显升高。三组中酵母组的MUFA含量是高为55％。主要是C16：1ω9（23％），而PUFA最低（16．6％），其中EPA（2．7％）、DHA（0．8％）等ω3HUFA含量均很低；与酵母组相比，海水小球藻组和有机肥组的MUFA含量显著下降，PUFA含量显著升高，均为30％－33％左右，三组中海水小球藻组EPA含量最高（14％），其次是有机肥组（5．9％）和酵母组（2．7％）；有机肥组DHA含量最高，达11．7％，而酵母组和海水小球藻组DHA含量均低，仅为0．7％－0．8％。经鱼油强化后，酵母组的MUFA含量显著下降，PUFA显著升高，EPA由2．7％提高到10％左右，DHA由0．8％以7％；酵母组经海水小球藻二次培养后MUFA显著降低，PUFA相应升高，EPA由2．7％提高到9．7％，而DHA含量无变化。     

华北落叶松种子贮藏试验浅析

在三种库房里对五种不同含水率、两种包装的华北落叶松种子进行了60个月的贮藏试验。结果认为，含水率5．19／5～8．0％的落叶松种子可以在三种库房密封贮藏39个月。种子贮藏的最佳含水率为6．6％～8．0%，最佳的库房是冷库(0C～5C)。磨口瓶与布袋在冷库贮藏效果差异不明显；地下库不能用布袋贮藏；在普通常温库中磨口瓶比布袋能多贮藏12个～18个月。     

尕海地区弃耕地土壤可溶性盐分测定

１９９０～１９９３年在柴达盆地尕海地区弃耕地进行土壤可溶性盐分测定，测定结果，该地区土壤盐分组成为氯化物－硫酸盐和硫酸盐－氯化物，大部分地区耕层盐分含量小于１０ｇ．ｋｇ＾－１，少部分盐荒地表层含盐量高达７０ｇ．ｋｇ＾－１，牧草生长季节中，土壤盐分含量最低期在６月份。     

Correlation between hydrolytic enzyme activities measured in bean seedlings afterTrichoderma koningii treatment combined with pregermination and the protective effect againstPythium splendens

An experimental protocol consisting in the colonisation of pregerminated bean seeds dressed withTrichoderma sp. was used in order to study the mechanisms correlated with the protective effect againstPythium splendens. Seed dressed with TH-11 (T. koningii) for 24 h presented a higher protective effect and a higher level of seed colonisation as compared to those dressed with TH-13 (T. longibranchiatum). The levels of seed coat colonisation by TH-11 and TH-13 was shown to be correlated with the carboxymethylcellulase activity, as measured in the seed coats retreived from germinating dressed bean seeds. The seed coat colonisation was also associated with an increased activities of endo-1,3--glucanase and endochitinase measured in seed extracts, and an inhibitory effect of seed extracts onPythium sporangia germination. Pretreatment of TH-13-dressed seeds with a commercial cellulase improved all parameters mentioned above, thus suggesting a role of cellulase activity in the colonisation process and the linked protective effect. The possible role of hydrolytic enzymes in the protective effects is discussed.