我国西北、西南地区牧草种子质量及其影响因素分析

１９９３和１９９４年，对我国西北、西南７省（区）主要生产、经销的１１种１１０个种批的牧草和草坪草种子进行了现场扦样、质量检验和质量定级，并对影响种子质量的因素进行了调查与分析。结果表明：被检种的平均合格率为７１．４％，其一、二、三级及不合格种子分别占３６．０％、１２．７％、２２．７％和２８．６％。种批的质量以进口坪用草地早熟禾、多年生黑麦草和国产苇状羊茅（坪用）和老芒麦质量最好，种批平均质量均达一级；其次为国产多年生黑麦草（坪用）和毛苕子，虽然各含三级和／或二级种子，但合格率为１００％。其它被检种质量较低，尤其是紫花苜蓿（１９９３年检）、沙打旺（１９９４年检）、苏丹草和红豆草，不合格种批率分别为６０％、７０％、８０％和１００％。种子质量低的主要表现为多数种杂质含量高和杂草种子严重超标，部分种发芽率低以及个别种水分含量过高。影响种子质量的主要因素为（１）种子生产不规范，技术落后；（２）生产和经营者缺乏必备的种子收获、清选机具以及种子收后质量管理知识；（３）种子经营混乱，信息不畅，产销脱节等。就如何尽快提高我国牧草种子质量以及加强种子质量管理等问题提出了建议。     

对芨芨草草场资源在鄂尔多斯市开发利用的建议

芨芨草草场广泛分布于内蒙古荒漠草原及草原化荒漠地带，也广泛分布于鄂尔多斯市。它适应性强，耐旱、耐寒、耐瘠薄，具有返青早，产量高，品质好等特点，家畜喜食。它既是优良牧草，又是用途广泛的经济植物和水土保持植物。     

Modelling the concentrations of nitrogen and water-soluble carbohydrates in grass herbage ingested by cattle under strip-grazing management

There is scope of increasing the nitrogen (N) efficiency of grazing cattle through manipulation of the energy and N concentrations in the herbage ingested. Because of asymmetric grazing by cattle between individual plant parts, it has not yet been established how this translates into the concentrations of N and water‐soluble carbohydrates (WSC) in the herbage ingested. A model is described with the objective of assessing the efficacy of individual tools in grassland management in manipulating the WSC and N concentrations of the herbage ingested by cattle under strip‐grazing management throughout the growing season. The model was calibrated and independently evaluated for early (April), mid‐ (June, regrowth phase) and late (September) parts of the growing season. There was a high correlation between predicted and observed WSC concentrations in the ingested herbage (R² = 0·78, P < 0·001). The correlation between predicted and observed neutral‐detergent fibre (NDF) concentrations in the ingested herbage was lower (R² = 0·49, P < 0·05) with a small absolute bias. Differences in the N concentration between laminae and sheaths, and between clean patches and fouled patches, were adequately simulated and it was concluded that the model could be used to assess the efficacy of grassland management tools for manipulating the WSC and N concentrations in the ingested herbage. Model application showed that reduced rates of application of N fertilizer and longer rotation lengths were effective tools for manipulating herbage quality in early and mid‐season. During the later part of the growing season, the large proportion of area affected by dung and urine reduced the effect of application rate of N fertilizer on herbage quality. In contrast, relative differences between high‐sugar and low‐sugar cultivars of perennial ryegrass were largest during this period. This suggests that high‐sugar cultivars may be an important tool in increasing N efficiency by cattle when risks of N losses to water bodies are largest. The model output showed that defoliation height affects the chemical composition of the ingested herbage of both the current and the subsequent grazing period.     

放牧水牛牧食量与胃肠道消化代谢的关系

本实验选用江苏省东台县种畜场9头成年母海仔水牛,于1984年5月至9月在草滩牧场进行了春、秋两期实验。秋季放牧期瘤胃内乙酸/丙酸(A/P)比值和pH值均显著高于春季放牧期;TVFA浓度和可消化干物质采食量也稍高于春季,但差异不显著(P>0.05)。放牧水牛瘤胃中TVFA变化较平稳,与采食量关系不甚明显。春季放牧期采食量和食糜排出速率均显著低于秋季;而表观消化率则显著高于秋季。春季放牧期采食量(Y),表观消化率(X_2)和食糜排出速率(X_1)三项指标两两之间均呈正相关,复回归方程为:Y=-10.48+0.2216X_1+0.1615X_2(r=0.70,P<0.05);秋季放牧期采食量与食糜排出速率呈正相关,但分别与消化率呈负相关,三者的复回归方程为:Y=-4.66+0.5239X_1+0.4662X_2(r=0.88,P<0.01)。本实验中放牧水牛的采食行为虽然受到选择性牧食、草生状态和放牧距离等外界因素的影响,但牧食量受食糜排出率和表观消化率的共同调节。     

亚高山草甸不同坡向牧草产量动态的研究

本文就山西亚高山草甸不同坡向牧草产量动态进行研究。三年定位研究结果表明，亚高山草甸牧草一般在四月中、下旬开始返青，随着气温的升高生长逐渐加快，牧草产量逐月增高，各坡向产草量动态均呈现单峰曲线变化规律。干草产量的峰值，东坡和西坡在七月，其它被向则出现在八月。九月上旬牧草开始枯萎，产草量开始下降，一直持续到翌年四月上旬牧草返青之前。牧草营养物质的变化，在生长前期粗蛋白质和磷含量高，随着牧草的生长发育逐渐减少，而粗纤维含量则相反。粗蛋白质产量高峰期，东、南和西坡在七月，北坡和山顶部在八月，与干草产量的高峰期基本吻合，此时正是牧草利用的最佳时期。除五、六月外其它各月青草期牧草产量和营养物质产量，北坡均显著高于其它各坡向（P＜0．05）。     

内生真菌对布顿大麦草生长的影响

植物生长室条件下，通过比较含（Ｅ＋）与不含（Ｅ－）内生真菌的布顿大麦草的生物量，分蘖数等指标，研究确定了内生真菌对寄主生长的影响。结果表明，与Ｅ－植株相比，Ｅ＋植株的总生物量增加３６．４％，地上部分牧草干物质产量增加３３．３％，根干重增加３０％，每株植株的分蘖数增加１３６．８％。     

几种温季禾本科牧草混播试验(1988～1989年)

本试验对纤毛鹅观草、苇状羊茅、鸭茅三个草种组成的4个混播组合进行产草量、越夏率的互比,并对混播与单播的产草量作了比较。结果以纤毛鹅观草+苇状羊茅+鸭茅组合最佳,4个混播组合产草量均比供试3个草种之任何一种单播高.     

渭北旱塬杨家陇实验分区牧草引种栽培试验研究

本文根据连续3年的田间试验结果,对引种栽培的20种牧草,从物候期、覆盖度、茎叶比、青干比、生长速度、鲜草产量及抗逆性等七个方面进行对比分析,筛选出了适合渭北旱塬东部地区生态条件的优质高产草种,它们是豆科牧草中的红豆草、沙打旺和草原二号苜蓿等,以及禾本科牧草中的多花黑麦草、苇状羊茅和无芒雀麦等。从而为当地人工种草,强化农牧结合奠定了基础。     

黄河三角洲地区野生牧草种质资源的初步研究

研究牧草种质资源，无论是对野生牧草种质的保存，鉴定，还是对培育利用用牧草建立人工草地，改良天然草地都有很大意义。本文为更好地发掘，利用野生牧草种质资源提供了一定的科学依据。