Grassland research priorities: Ideas for the future     

D.I. Bransby 《African Journal of Range and Forage Science》2013,30(1):14-15

Abstract

Four levels of available dry matter (DM) were maintained on a continuously grazed irrigated Midmar Italian ryegrass (Lolium multiflorum Lam.) pasture by means of a “put‐and‐take” grazing procedure. The pasture was stocked with three successive sets of weaned lambs in winter, spring and early summer respectively. The relation between average daily gains (ADG) and available DM was positively linear At equivalent levels of available DM, gains were greater in spring than in either the winter and summer periods (P ≤0,01), but there were no differences in gains between winter and summer. There was a negative linear relation between average stocking rate (the rate required to achieve a given level of herbage availability) and available DM. Stocking rates in spring and summer were not significantly different, but both were higher (P≤0,01) than those in winter. Within the range of the differential treatments applied, relations between stocking rate and ADG were negatively linear, and there was an interactive effect (P≤0,01) between stocking rate and grazing period. Changes in ADG with a unit change in stocking rate were greatest in winter, intermediate in summer and least in spring. Gains/ha were curvilinearly related to available DM. The curves indicate that the amounts of available DM required for maximum gains/ha were least in spring, intermediate in summer and greatest in winter.

From a serial cutting trial conducted concurrently with the grazing, a growth rate curve was developed for Midmar ryegrass. This curve had two maxima, with the maximum growth rate in spring being more than double that in autumn. The in vitro digestible organic matter content and crude protein content decreased from 80,6% and 24,1% in autumn to 63,1% and 10,6%, respectively, in summer. Crude fibre content increased from 10,1 % in autumn to 30,1 % in summer.  相似文献   

Growth patterns of Italian ryegrass cultivars established in different seasons     

D.C.W. Goodenough  C.I. Macdonald  A.R.J. Morrison 《African Journal of Range and Forage Science》2013,30(3):21-24

Abstract

A comparison is made between various Italian ryegrass cultivars established under irrigation on a well‐drained upland site during the traditional autumn months, with plantings of the same cultivars at other times of the year.

The dates on which pastures could be utilized for the first time, their relative growth patterns as well as weed infestation, flowering behaviour and persistency, were investigated. Some herbage quality determinations were also made.

February plantings are considered the most favourable for maximum late autumn, winter and spring production. First utilization following late autumn/winter plantings is, however, delayed considerably with the onset of cold weather. Late winter/early spring plantings, on the other hand, delay flowering for up to 16 months and the biennial growth pattern indicates vigorous growth immediately after planting, the possibility of variable late summer production followed by extremely poor autumn and winter production. This casts serious doubt on the merit of such a practice at the total exclusion of the traditional autumn plantings. Summer weed infestation from such spring plantings also gave cause for concern.  相似文献   

The effect of the nitrification inhibitor dicyandiamide (DCD) on spring and annual herbage production in urine patches when applied in late summer or early autumn     

P. J. O'Connor  M. B. Lynch  E. Cahalan  M. O'Donovan  D. Hennessy 《Grass and Forage Science》2013,68(4):564-576

A cut plot experiment was undertaken at two sites in Ireland, one a free‐draining acid brown earth at Moorepark (MPK) and the other a fine loam soil with imperfect drainage at Johnstown Castle (JC). The effect of applying the nitrification inhibitor dicyandiamide (DCD) at 10 kg ha^?1 in July, August and September or not applying DCD to plots receiving synthetic urine or zero urine on spring and annual herbage production was examined. In the experiment, each site received 350 kg nitrogen (N) fertilizer ha^?1 year^?1. The application of DCD in August at a rate of 10 kg ha^?1 significantly increased spring and annual herbage production by 14 and 15%, respectively, at MPK, when applied following urine application in year 1. There was no effect of DCD applied in year 1 on herbage production at JC. The application of DCD in August resulted in lower soil total oxidized N (TON) content up to sampling day 56 post‐urine application, at MPK in year 1, retaining higher N content in the soil. There was no effect of DCD on any of the parameters measured in year 2 at MPK or at JC. Urine application did not increase spring herbage production at either site. Urine application significantly increased annual herbage production at MPK only in year 1. Urine application increased annual herbage N uptake, herbage crude protein (CP) content and soil mineral N at both sites in both years.  相似文献   

香梨果园套种苏丹草对土壤养分及产草量的影响     

叶尔兰·对山别克  艾比布拉·伊马木 《西北林学院学报》2019,(4):139-144

探讨库尔勒香梨果园套种苏丹草对果园土壤性状的影响和产草量。果园内,分别设距树干0.5m处外和1.5m处外2个采样区,测定采样区内苏丹草产量和0~60cm土层的土壤容重及土壤养分。结果表明,离树干1.5m处外干草产量为2.25kg/m^2,显著高于离树干0.5m处外的1.34kg/m^2。离树干0.5m处外0~20、20~40cm土层地下生物量分别为81.26g/m^2、14.38g/m^2约为离树干1.5m处213.62g/m^2、32.89g/m^2的38.03%、56.27%,且90%以上的牧草根量分布在0~20cm的果园土层,苏丹草与果树的根系几乎无重叠现象。可见,香梨果园套种苏丹草对土壤性状及养分无负面影响,1a可以收草3次,其产草量可达大田产量的60%左右。  相似文献   

典型黑土区陡坡植草水土流失防治效果研究   总被引：1，自引：0，他引：1  

杨庆楠  徐金忠  李志飞  侯淑艳  郝燕芳 《水土保持通报》2019,39(6):117-123

[目的]研究陡坡生物防治与影响因素的变化关系,为侵蚀沟治理、水土保持植被措施配置等决策提供科学依据。[方法]设置2个坡度,7种草本植被配置模式,于2018年6—9月开展了自然小区水土流失监测。[结果] 1∶1.5和1∶1.2坡比边坡草本建植当年分别较裸地平均减流27%和26%,减沙52%和21%,坡度由34°增加到40°,地表径流虽未增加,但土壤侵蚀量明显增加;影响产流产沙的降雨因子主要有雨量,I_(30),E,EI_(30),坡度变陡,相关性增强;建植草无芒雀麦和紫花苜蓿混播减流减沙效果最好,紫花苜蓿、无芒雀麦、早熟禾3种草种混播减流效果优于单播;1∶1.2坡比边坡随着植被盖度的增加减沙效果逐渐增强,且在植被盖度大于50%时减沙效果接近1∶1.5坡比边坡。[结论]在无芒雀麦和紫花苜蓿混播草本配置下,1∶1.2坡比削坡在侵蚀沟治理时可采用,能减少20%的削坡占地面积。  相似文献   

Simultaneous selection for seed and forage production in cocksfoot (Dactylis glomerata): application of drought tolerance and susceptibility indices          下载免费PDF全文

M. M. Majidi  B. Hoseini  M. Barati  A. Mirlohi  B. Araghi 《Grass and Forage Science》2017,72(3):441-453

An experiment was conducted to estimate drought tolerance of some cocksfoot genotypes based on seed and forage yield and related indices (including tolerance index, mean productivity, geometric mean productivity, reduction percentage index, stress tolerance index and stress susceptibility index) and to identify relationships between measured traits. Twenty‐five genotypes were evaluated in the field under control and drought‐stress environments over 2 years. The results revealed a high variation for seed yield and forage yield and the measured indices under both moisture conditions. No correlation was observed between seed yield and forage yield under the control treatment, but this correlation was positively significant under the water‐stress treatment. Drought‐tolerant and susceptible genotypes were identified based on seed and forage yield performance. Genotypes 2, 4 and 7 had high seed yield, while genotypes 7 and 10 had high forage yield under both stressed and non‐stressed conditions and were identified as the most tolerant genotypes in each category. The results also revealed that genotypes 1, 2, 4, 6, 7, 8 and 24 had relatively high seed and forage yield in both control and drought‐stressed conditions. These genotypes can be used for further studies to improve both seed and forage yields concurrently.  相似文献   

江苏沿海滩涂发展牧草业的前景     

杨智青  丁海荣  陈应江  洪立洲  徐文华  杨凌 《家畜生态》2008,(4)

对江苏沿海地区的地理状况以及牧草产业的发展现状进行全面的描述,同时针对沿海地区滩涂土地后备资源丰富的特点,从当地农村产业结构、养殖业、牧草经济价值以及东部沿海开放型牧草业的发展前景等几个方面阐述。在江苏沿海地区,利用滩涂资源丰富优势,结合农村产业结构调整,发展滩涂牧草种植业,能够促进当地畜牧业的良性循环,改良滩涂土壤,提高滩涂的利用水平。  相似文献   

伊克昭盟牧草和饲料作物应用增产菌技术的试验     

余奕东  韩勇军等 《内蒙古草业》1999,(4):47-53

199年伊克昭盟引入了牧草和饲料作物增产菌这一技术,经过7年的试验,示范及推广,至今全盟该增产菌应用面积已达4．04万hm^2,本文通过7年来在两种不同生境下,对12种牧草及作物的不同物修期采用不同方法施用增产菌,以鲜草产量和种子产量为衡量标准来探讨增产菌对不同牧草及作物的增产效果,实验结果表明：增产菌技术的应用,促进了植物的生长,使植株长高,叶面积增大,加强了光合作用,在提高鲜草产量的同时也增加了籽实的产量,具有较强的推广价值,是一项在农牧区适用的增产技术。  相似文献   

青南高原气候变化及其对高寒草甸牧草生长影响的研究   总被引：57，自引：2，他引：55  

张国胜  李林 《草业学报》1999,8(3):1-10

通过对１９６１年以来青南高原气候变化的分析,发现该地区年平均降水量及秋季降水量无明显的变化趋势,且其年际间的波动趋于缓和;冬季（１２－２月）和春季（３－５月）降水量的变化趋势呈现出逐年增多的趋势,气候倾向率分别为２．６ｍｍ／１０ａ和３．６ｍｍ／１０ａ;夏季降水量变化却表现出显著的减少趋势,其倾向率为－６．５ｍｍ／１０ｓ。  相似文献   

聚乙二醇引发对几种牧草种子发芽率和活力的影响   总被引：26，自引：4，他引：22  

孙建华  王彦荣 《草业学报》1999,8(2):34-42

应用聚乙二醇（ＰＥＧ）引发法探讨了不同引发渗透势、时间处理对无芒雀麦、苏丹草、沙打旺、小冠花、紫花芷蓿等牧草种子萌发和活力和有性在适宜处理下供试种子发芽速度、发芽率及活力指数分别显著高于对照;ＰＥＧ的引发作用还表现为提高活力效应大于提高发芽率效应,学表明,低渗透势（－０．１、－１．２、－１．５ＭＰａ）引发处理对提高发芽率无作用;但处子早期萌发的效应对于沙打旺和小冠花种子的２仍很强烈,对苏丹草种子则  相似文献