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1.
扁蓿豆生长发育规律的研究 总被引:2,自引:0,他引:2
通过4年的种植观察发现,种植第1年扁蓿豆和苜蓿生长都较缓慢,扁蓿豆的越冬率在l~4年内随着生育年限的增加而提高,而苜蓿的越冬率比扁蓿豆稍低.返青都在4月末,从返青到成熟期的生育天数扁蓿豆为120d,苜蓿为103d.生活第2年的扁蓿豆草层最大鲜量出现在30~40cm处,其中叶量占52.4%;生活第2年和生活第3年的苜蓿草层结构最大鲜量都出现在40~50cm处,分别为50.6g和55.2g,比扁蓿豆分别少了12.4g和7.2g.种子产量第3年最高,扁蓿豆为188.4kg/hm2,苜蓿为211.95kg/hm2.扁蓿豆的生育期较长,第1年为150d,第2年为125d,第3年为120d;而生活第2年的苜蓿生育期为120d,第3、4年都为103d. 相似文献
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Abstract. A forage model (FORYLD) was used to estimate average potential (constraint-free) yields ( B y ) and yields under rainfed conditions ( B ya ) of alfalfa and wheatgrasses for the prairie region of Western Canada. Yield estimates were determined using 30-year climatic means (monthly values) and assumed available water-holding capacities (AWC) of soils ranging from 50 to 280 mm as inputs to the model. Calculations were made for 252 areas or zones known as Agroecological Resource Areas (ARAs) for the region. Estimates of B y for alfalfa ranged from over 17.5 t/ha, in areas where three cuts of alfalfa were feasible if the crop were fully irrigated, to less than 10 t/ha in some northern ARAs where restricted length of the growing season limited potential to only one cut. For wheatgrasses B y ranged from 15 to 17.5 t/ha in most areas where two cuts are possible. Estimates of B ya for alfalfa, based on the predominant AWC for soils in each ARA, ranged from less than 2 t/ha in the driest portion of the prairie region to more than 8 t/ha in the more humid areas. Yields of wheatgrasses were very similar to those of alfalfa in the driest zones but slightly more in some of the more humid regions. Effects of varying soil AWC on yield estimates are presented for the major soil groups of the prairies. 相似文献
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Die resultate van ‘n studie van die reaksie van twee belangrike eenjarige weidingsgrasse van Suidwes‐Afrika, Schmidtia kalahariensis en Enneapogon cenchroides, teenoor verskillende omgewingsfaktore word gerapporteer. Verskille tussen die twee spesies ten opsigte van ligenergievereistes, lengte van die lewensiklus, voedingsbehoeftes, smaaklikheid (veroorsaak deur suurafskeidmg) en ontkiemingseienskappe is uitgewys. Dit is moontlik om hierdie verskille in verband te bring met die natuurlike verspreiding van die twee spesies. 相似文献
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为了缓解牧业冬春季节饲草不足的问题,有效利用8—10月的水、热、光和土地资源,复种青刈秣食豆,明确秋闲田秣食豆的高产栽培技术,促进良种良法配套技术推广应用。采用正交试验与软件PASW Statistics 18的LSD法,以秣食豆产草量为主要考核指标,对秋闲田秣食豆播种行距、种植密度与氮、磷、钾等影响因素进行比较试验。结果表明,密度、行距与钾肥对秋闲田秣食豆产草量具有重要影响。明确了秋闲田秣食豆高产配套栽培技术的优化方案:每公顷留苗密度75万株,并以氮肥(N)300 kg/hm2、磷肥(P2O5)112.5 kg/hm2、钾肥(K2O)375 kg/hm2做基肥,播种方式以50 cm的行距进行条播。该方案的鲜草产量、干草产量分别为6661.67 kg/hm2、2723.64 kg/hm2,较产草量位居第二的优良组合的鲜重、干重分别增产24.17%、27.63%。为秋闲田栽培秣食豆的生产实践提了供理论依据和技术支撑。 相似文献
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Katarzyna Slizewska Adriana Nowak Zdzislawa Libudzisz Janusz Blasiak 《Research in veterinary science》2010,89(3):391-395
The aim of the study was to evaluate the influence of a probiotic preparation on the genotoxicity of faecal water of broiler chickens fed with a fodder contaminated with aflatoxin B1 (AFB1) at 1 or 5 mg per kg. Human blood lymphocytes were exposed to chicken’s faecal water samples and DNA damage was measured using the comet assay. Genotoxicity of faecal water did not depend on the AFB1 concentration in the fodder. The mean DNA damage, measured as the percentage of DNA in the tail of the comets, for chickens fed with fodder with AFB1 at 1 mg/kg was 16.80 ± 0.66, at 5 mg/kg – 16.73 ± 1.51 and in the controls – 12.79 ± 0.66. The supplementation of fodder with the probiotic preparation decreased the extent of DNA damage to 10.02 ± 0.39 for 1 mg/kg AFB1 and to 11.89 ± 0.72 for 5 mg/kg. 相似文献
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Increasing water productivity of irrigated crops under limited water supply at field scale 总被引:1,自引:0,他引:1
Borkhar district is located in an arid to semi-arid region in Iran and regularly faces widespread drought. Given current water scarcity, the limited available water should be used as efficient and productive as possible. To explore on-farm strategies which result in higher economic gains and water productivity (WP), a physically based agrohydrological model, Soil Water Atmosphere Plant (SWAP), was calibrated and validated using intensive measured data at eight selected farmer fields (wheat, fodder maize, sunflower and sugar beet) in the Borkhar district, Iran during the agricultural year 2004-2005. The WP values for the main crops were computed using the SWAP simulated water balance components, i.e. transpiration T, evapotranspiration ET, irrigation I, and the marketable yield YM in terms in terms of YMT−1, YM ET−1 and YM I−1.The average WP, expressed as $ T−1 (US $ m−3) was 0.19 for wheat, 0.5 for fodder maize, 0.06 for sunflower and 0.38 for sugar beet. This indicated that fodder maize provides the highest economic benefit in the Borkhar irrigation district. Soil evaporation caused the average WP values, expressed as YM ET−1 (kg m−3), to be significantly lower than the average WP, expressed as YMT−1, i.e. about 27% for wheat, 11% for fodder maize, 12% for sunflower and 0.18 for sugar beet. Furthermore, due to percolation from root zone and stored moisture content in the root zone, the average WP values, expressed as YMI−1 (kg m−3), had a 24-42% reduction as compared with WP, expressed as YM ET−1.The results indicated that during the limited water supply period, on-farm strategies like deficit irrigation scheduling and reduction of the cultivated area can result in higher economic gains. Improved irrigation practices in terms of irrigation timing and amount, increased WP in terms of YMI−1 (kg m−3) by a factor of 1.5 for wheat and maize, 1.3 for sunflower and 1.1 for sugar beet. Under water shortage conditions, reduction of the cultivated area yielded higher water productivity values as compared to deficit irrigation. 相似文献