We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was t...We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.展开更多
为了提高饲用苎麻营养价值,本研究采用随机区组设计,以苎麻饲用专用品种“中饲苎1号”为研究试材,通过两年大田试验和一年盆栽试验,土壤基施不同量亚硒酸钠(0、0.25、0.50、0.75和1.00 kg Se·hm-2),研究外源硒对饲用苎麻草产量、...为了提高饲用苎麻营养价值,本研究采用随机区组设计,以苎麻饲用专用品种“中饲苎1号”为研究试材,通过两年大田试验和一年盆栽试验,土壤基施不同量亚硒酸钠(0、0.25、0.50、0.75和1.00 kg Se·hm-2),研究外源硒对饲用苎麻草产量、粗蛋白、粗脂肪、粗灰分、中性洗涤纤维、酸性洗涤纤维、相对饲喂价值和营养元素硒(Se)、磷(P)、钾(K)及钙(Ca)含量的调控。结果表明,外源硒对饲用苎麻草产量无显著性影响,而对其营养价值有一定的影响,但变化幅度因施硒量、年份和刈割时间有所不同。与对照相比(0 kg Se·hm-2),0.25、0.50、0.75和1.00 kg Se·hm-2处理中2年大田试验平均粗蛋白含量分别提高1.52%、0.96%、-0.10%和-4.29%;粗脂肪含量分别下降0.25%、3.93%、1.54%和9.34%;粗灰分含量分别提高1.37%、1.23%、2.29%和0.85%;酸性洗涤纤维含量分别增加1.92%、2.15%、2.32%和3.22%;中性洗涤纤维含量变幅分别为-2.97%、-0.97%、2.01%和2.63%;相对饲喂价值变幅分别为1.74%、-0.103%、-3.14%和-4.30%;Ca含量变幅分别为0.07%、-2.01%、1.27%和-0.59%;P含量分别提高7.26%、7.68%、4.63%和4.54%;K含量分别变幅分别为4.59%、12.31%、-2.04%和2.83%;Se含量随着施硒量的增加逐渐增加,最高可达到2.07 mg·kg-1。通过主成分分析结合模糊数学中隶属函数法综合评价表明,0.25~0.50 kg Se·hm-2为该地区效果最佳施硒量,有利于提高饲用苎麻的营养价值。展开更多
文摘We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.
文摘为了提高饲用苎麻营养价值,本研究采用随机区组设计,以苎麻饲用专用品种“中饲苎1号”为研究试材,通过两年大田试验和一年盆栽试验,土壤基施不同量亚硒酸钠(0、0.25、0.50、0.75和1.00 kg Se·hm-2),研究外源硒对饲用苎麻草产量、粗蛋白、粗脂肪、粗灰分、中性洗涤纤维、酸性洗涤纤维、相对饲喂价值和营养元素硒(Se)、磷(P)、钾(K)及钙(Ca)含量的调控。结果表明,外源硒对饲用苎麻草产量无显著性影响,而对其营养价值有一定的影响,但变化幅度因施硒量、年份和刈割时间有所不同。与对照相比(0 kg Se·hm-2),0.25、0.50、0.75和1.00 kg Se·hm-2处理中2年大田试验平均粗蛋白含量分别提高1.52%、0.96%、-0.10%和-4.29%;粗脂肪含量分别下降0.25%、3.93%、1.54%和9.34%;粗灰分含量分别提高1.37%、1.23%、2.29%和0.85%;酸性洗涤纤维含量分别增加1.92%、2.15%、2.32%和3.22%;中性洗涤纤维含量变幅分别为-2.97%、-0.97%、2.01%和2.63%;相对饲喂价值变幅分别为1.74%、-0.103%、-3.14%和-4.30%;Ca含量变幅分别为0.07%、-2.01%、1.27%和-0.59%;P含量分别提高7.26%、7.68%、4.63%和4.54%;K含量分别变幅分别为4.59%、12.31%、-2.04%和2.83%;Se含量随着施硒量的增加逐渐增加,最高可达到2.07 mg·kg-1。通过主成分分析结合模糊数学中隶属函数法综合评价表明,0.25~0.50 kg Se·hm-2为该地区效果最佳施硒量,有利于提高饲用苎麻的营养价值。
