共查询到18条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
不同放牧强度对草地土壤含水量、草地生产性能和绵羊增重的影响 总被引:3,自引:0,他引:3
家畜通过放牧采食及践踏植物直接影响草地,改变植物覆盖的种类和数量;家畜放牧对植被的间接影响将造成表土紧实或松散,减少覆盖,减少土壤水分。2004年5月份,在宁夏南部山区海原县围栏封育区进行试验,旨在掌握不同放牧强度下土壤水分、地上生物量以及放牧羊只体重的变化,从而为同类地区确定科学合理的载牧量提供参考依据。 相似文献
6.
7.
贵州威宁地区栽培草地的建植常以鸭茅(Dactylis glomerate)和白三叶(Trifolium repens)为主,通过在建植均匀的草地上进行分群分区放牧,研究了不同羊群的放牧强度对人工栽培草地植被和土壤特征的影响。结果表明:高强度放牧利用下的群落高度和地上生物量显著降低(P<0.05),而低度和中度放牧处理下的群落高度和生物量均没有显著性变化(P>0.05);放牧利用降低了鸭茅和白三叶的频度和盖度;放牧利用对表层土壤容重的影响不显著(P>0.05),但是在高放牧压力处理中,10~30cm土层土壤容重比其他处理平均升高32%;放牧对土壤化学性质有显著影响(P<0.05),随着放牧强度的增加,土壤养分含量呈下降趋势。综合草产量和草地恢复能力分析,贵州威宁地区的栽培草地最适载畜量应该在17~23SU/hm^2。 相似文献
8.
不同放牧强度对牦牛生长和草地第二生产力的影响 总被引:6,自引:2,他引:4
试验研究了6种放牧强度对牦牛生长及草地第二性生产力的影响,结果表明,放牧强度对牦牛日增重有明显影响,日增重以0.24牦牛单位/hm^2处理组最高,达707.9g随着放牧强度的增大,牦牛日增重明显降低。其中,放牧强度对1岁牦牛影响最大,2岁牦牛次之,3岁牦牛再次。试验全期当放牧强度于1.2牦牛单位/hm^2时,增大放牧强度,草地第二性生产力明显提高,当放牧强度高于1.2牦牛单位/hm^2时,增大放牧 相似文献
9.
10.
放牧强度对草地土壤理化性质的影响 总被引:66,自引:5,他引:66
在河北省承德鱼儿山牧场研究不同放牧强度对草地土壤理化性质的影响,研究结果表明:随放牧强度增加,土壤表层0-10cm容重增大,土壤变得紧实,渗透性降低;土壤全磷和速效磷含量降低,而全氮和速效钾含量增加。 相似文献
11.
本文以晋北农牧交错带半干旱草地生态系统为研究对象,于2016年设置不放牧、轻度、中度和重度放牧4个不同放牧强度试验,研究短期放牧强度下羊对草地植物群落多样性与生产力的影响,以确定最佳放牧强度。研究结果表明,植物群落多度随放牧强度增加呈先升后降趋势,高度与盖度则随放牧强度的增加逐渐降低;物种多样性在中度放牧最高,重度放牧时最低;植物地上生物量随放牧强度增加呈抛物线形式变化,中度放牧时最高,分别为757.04 g·m-2和398.37 g·m-2,植物地下生物量随放牧强度增加逐渐降低;草地土壤容重随放牧强度的增加逐渐增大。短期放牧下中度放牧的植物群落多度、物种多样性与地上生物量最高,轻度放牧植物群落高度、盖度和地下生物量最高,重度放牧的物种多样性与生产力较低,因此适度放牧有利于保持草地植物群落稳定。 相似文献
12.
基于高寒草地放牧系统次级生产力的优化放牧强度研究 总被引:1,自引:0,他引:1
依据小嵩草(Kobresia parva)高寒草甸和垂穗披碱草(Elymus nutans)/星星草(Puccinellia tenuflora)高寒混播人工草地牦牛放牧系统、紫花针茅(Stipa purpurea)高寒草原藏系绵羊放牧系统中草地次级生产力(家畜增重)的试验数据,构建了放牧家畜个体增重与放牧强度之间的模型:Y=a-bX(b>0),以此为基础确定了单位面积草地次级生产力(家畜增重)与放牧强度之间的数学模型:Y=aX-bX2(b>0);计算出各放牧系统最大生产力放牧强度:高寒草甸冷季和暖季草场分别是1.68头·hm-2和2.52头·hm-2,高寒人工草地牧草生长季为7.23头·hm-2,高寒草原冷季、暖季和全年连续放牧草场分别是4.33,6.45,2.36只·hm-2。 相似文献
13.
14.
15.
16.
17.
《Strength and Conditioning Journal》2020,73(2):252-258
Understanding fall precipitation effects on rangelands could improve forage production forecasting and inform predictions of potential climate change effects. We used a rainout shelter and water addition to test effects of seasonal precipitation on soil water and annual net primary production of C3 perennial grass, C4 perennial grass, annual grasses, forbs, and all plants combined. Treatments were 1) drought during September−October and April−May (DD); 2) drought plus irrigation during September−October and drought during April−May (WD); 3) year-long ambient conditions (WW); and 4) ambient plus irrigation during September−October (W + W). Treatments created conditions ranking among the driest and wettest September−October periods since 1937. Fall water effects on soil water were not detectable by May at 15 cm and 30 cm. Effects persisted into July at 60 cm and 90 cm, depths below the primary root zone. With spring drought, annual net primary production was 344 kg ha−1 greater when the previous fall was wet rather than dry. No differences were detected between fall water treatments when spring was wet and fall was about 184% (1 938 ± 117 kg ha−1) or 391% of the median (1 903 ± 117 kg ha−1). Fall water increased C3 perennial grass when spring was also wet and had no effect under spring drought, when forage production concerns are greatest. Fall water did not affect C4 perennial grass, and extremely wet fall conditions reduced forb production about 50%. The greatest effect of fall water was increased annual grass production. Even record high levels of fall water had minor effects on biomass, functional group composition, and soil water that were short-lived and overwhelmed by the influence of spring precipitation. Movement of fall water to deep soil by the growing season suggests plants that would most benefit from fall precipitation are those that could use it during fall (winter annuals), or deep-rooted species (shrubs). 相似文献
18.
放牧强度对高寒混播草地群落结构的影响 总被引:3,自引:1,他引:2
董全民 《青海畜牧兽医杂志》2007,37(2):1-3
垂穗披碱草/星星草混播草地三个放牧季的放牧试验结果表明:(1)植物群落盖度与放牧强度呈显著的负相关;(2)垂穗披碱草地上现存量的比例随放牧强度的增加而呈下降趋势,星星草和杂类草的比例呈上升趋势;(3)随放牧强度的增加,建群植物垂穗披碱草和星星草的株高呈下降趋势;(4)对照区与其它各放牧区植物群落的相似性系数随放牧强度的增加而减小,说明各放牧处理组植物群落朝着远离对照群落的方向演替。 相似文献