冬春季节补饲精料对BMY牛育肥性能的影响

[目的]冬春枯草季节,为研究在不同饲养水平下对6-9月龄BMY公牛增重性能的影响。[方法]以6-9月龄BMY公牛为育肥对象,5种育肥方式分别为：对照组全放牧不设补饲;试验1组采用放牧＋补饲1.0 kg精料;试验2组采用全舍饲（粗饲料自由采食,补饲1.0 kg/d精料）;试验3组采用全舍饲（粗饲料自由采食,补饲2.0 kg/d精料）;试验4组采用全舍饲（粗饲料自由采食,补饲3.0 kg/d精料）。[结果]表明：6-9月龄BMY公牛在冬季全放牧条件下育肥,体重不会增加反而会减少,平均日增重（ADG）为-178 g;在冬季放牧＋补饲1.0 kg精料的情况下,ADG为395 g;在舍饲＋1.0 kg精料、舍饲＋2.0 kg精料和舍饲＋3.0 kg精料的情况下,ADG分别达600 g7、28 g和1,023 g,补饲效果差异极显著（P〈0.01）,表明BMY牛在舍饲条件下生长更快,可获得更高的ADG。随着补饲日粮营养水平的提高,随着BMY牛日粮干物质采食量增加,说明补饲精料有利于粗饲料的摄入,从而增加ADG。[结论]冬春枯草季节补饲精料,无论放牧还是舍饲,6-9月龄BMY公牛均有较好的ADG,以舍饲加补饲精料的增重效果最为明显,可获得理想的经济收益。     

山核桃营养价值与种植经济效益分析

重点分析了山核桃的营养价值和石漠化地区种植山核桃的经济效益,通过分析得出：山核桃营养价值高,与其他坚果相比,山核桃在脂肪、膳食纤维、氨基酸等营养元素的含量上具有优势;以重庆市秀山县为例,通过调查分析得出：14年生山核桃林纯收入1273530元/hm2,产投比为9.74,投资收益为8.74。与当地常见农作物按照经济效益作比较,山核桃>金银花>烤烟>水稻>甘薯>玉米。     

甘蔗套种马铃薯多种密度栽培技术研究

为研究甘蔗套种马铃薯的最佳播种密度,提高土地复合产值,实现种植效益最大化。通过连续2 a开展新植蔗和宿根蔗套种马铃薯多种密度栽培试验,研究不同种植条件下甘蔗和马铃薯的产量、品质及经济效益。结果表明,新植蔗田中马铃薯的最佳套种密度为4.5万粒/hm2,宿根蔗田中马铃薯的最佳套种密度为3.9万粒/hm2。其中,新植蔗田马铃薯产量达35 275 kg/hm2,甘蔗产量增19.9%,糖锤度提高1.2个百分点,土地复合产值增99.7%,新增纯收入126.3%;宿根蔗田马铃薯产量达24 115 kg/hm2,甘蔗产量增19.2%,糖锤度提高1.3个百分点,土地复合产值增89.9%,新增纯收入110.5%。     

南漳县不同烤烟新品种适宜施肥量研究

在南漳烟区,以中烟102和中烟103为试材,研究了不同施氮量对烤烟生育期、农艺性状和经济性状的影响。结果表明:中烟103表现较好,农艺性状和经济性状均优于中烟102,适宜在南漳烟区种植,施氮量以75 kg/hm2为宜。     

不同热源烘烤节本增效试验研究

试验以普通燃煤热源为对照,对秸秆气化热源烘烤能耗、用工成本、烤后烟叶外观质量、节本增效效果等方面进行研究。结果表明:中、上部叶烘烤秸秆气化较普通燃煤烘烤能耗成本分别降低0.05、0.12元/kg干烟,烘烤用工成本均节省约60%,节本增效效果分别为0.45、0.43元/kg干烟,烟叶烤后外观质量无明显差异。     

不同氮肥类型对玉米产量和经济效益及氮肥利用率的影响

在大田试验条件下,采用随机区组设计了5个施氮水平,研究了不同类型尿素及用量对玉米干物质量、叶面积指数、籽粒产量、经济效益及氮肥利用率的影响。结果表明：包膜复合肥处理的开花前玉米的地上部干重、叶面积指数与常规尿素处理差异较小,开花后显著高于常规尿素处理,收获时其籽粒产量显著高于常规尿素处理。施包膜复合肥能显著提高玉米的籽粒产量、经济效益及氮肥利用率。     

施用电解锰渣对小麦叶绿素含量和经济性状的影响

通过盆栽试验研究了施用电解锰渣对小麦生长期叶绿素含量和经济性状的影响。结果表明:施用电解锰渣明显提高了小麦叶片叶绿素含量,使小麦的株高、穗粒数、千粒重、穗长增加,分别比对照增加5.0%、53.9%、28.8%、10.4%。     

我国经济开放、地区分割影响技术差距的实证分析

采用我国1992~2007年的省际面板数据,以我国商品市场分割和省际贸易合作来度量地区分割,发现我国地区分割程度不断下降;进一步分析地区分割、经济开放影响地区技术差距的机制,建立技术差距的影响因素模型。实证结果表明,地区分割妨碍落后地区的技术进步,加剧了我国地区间的技术差距;扩大出口贸易,提高引资份额在一定程度上有利于落后地区的技术收敛;研发、市场化改革对技术差距的缩小也有积极作用。     

中国经济的现实与未来:分析与展望

中国的长期发展使其经济实力和国际影响力显著增强,并使得人民币开始成为国际货币市场中的另一种财富标志。虽然对中国的可持续发展能力和政府作用仍存在种种质疑,但通过产业结构的调整和政治体制改革的深化,中国应能保持其发展趋势并在未来的多极世界中获得更大的话语权。     

Pest-damage relationships for Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) on soybean (Glycine max) and dry bean (Phaseolus vulgaris) during pod-fill

The response of soybean (Glycine max) and dry bean (Phaseolus vulgaris) to feeding by Helicoverpa armigera during the pod-fill stage was studied in irrigated field cages over three seasons to determine the relationship between larval density and yield loss, and to develop economic injury levels. H. armigera intensity was calculated in Helicoverpa injury equivalent (HIE) units, where 1 HIE was the consumption of one larva from the start of the infestation period to pupation. In the dry bean experiment, yield loss occurred at a rate 6.00 ± 1.29 g/HIE while the rates of loss in the three soybean experiments were 4.39 ± 0.96 g/HIE, 3.70 ± 1.21 g/HIE and 2.12 ± 0.71 g/HIE. These three slopes were not statistically different (P > 0.05) and the pooled estimate of the rate of yield loss was 3.21 ± 0.55 g/HIE. The first soybean experiment also showed a split-line form of damage curve with a rate of yield loss of 26.27 ± 2.92 g/HIE beyond 8.0 HIE and a rapid decline to zero yield. In dry bean, H. armigera feeding reduced total and undamaged pod numbers by 4.10 ± 1.18 pods/HIE and 12.88 ± 1.57 pods/HIE respectively, while undamaged seed numbers were reduced by 35.64 ± 7.25 seeds/HIE. In soybean, total pod numbers were not affected by H. armigera infestation (out to 8.23 HIE in Experiment 1) but seed numbers (in Experiments 1 and 2) and the number of seeds/pod (in all experiments) were adversely affected. Seed size increased with increases in H. armigera density in two of the three soybean experiments, indicating plant compensatory responses to H. armigera feeding. Analysis of canopy pod profiles indicated that loss of pods occurred from the top of the plant downwards, but with an increase in pod numbers close to the ground at higher pest densities as the plant attempted to compensate for damage. Based on these results, the economic injury levels for H. armigera on dry bean and soybean are approximately 0.74 HIE and 2.31 HIE/m², respectively (0.67 and 2.1 HIE/row-m for 91 cm rows).