Rumen degradation characteristics of sweet potato foliage and performance by local and crossbred calves fed milk and foliage from three cultivars

The study investigated rumen dry matter (DM) degradability characteristics in a completely randomized design and the effects of milk, sweet potato foliage (SPF) from three cultivars (A = TIS-87/0087; B = TIS-8164; C = TIS-2532.OP.1.13), dried brewers' grains (DBG) and cottonseed meal (CSM) as supplements to Panicum maximum (Panicum) for pre-weaned calves in randomized complete block designs. Diet 1 = milk + SPF-A foliage + Panicum, Diet 2 = milk + SPF-B foliage + Panicum, Diet 3 = milk + SPF-C foliage + Panicum, and Diet 4 = milk + DBG & CSM + Panicum (as control). Dry matter (130 ± 0.4 to 864 ± 3.9 g kg^− 1), ash (54 ± 4.2 to 173 ± 2.8 g kg^− 1 DM), OM (827 ± 4.2 to 946 ± 5.7 g kg^− 1 DM), N (7.4 ± 0.6 to 38.6 ± 1.4 g kg^− 1 DM), and NDF (439 ± 1.4 to 774 ± 8.5 g kg^− 1 DM) contents were highly significant (P < 0.01). In Trial I, 16 pre-weaned calves were used over 70 d with milk intake (34.8 ± 4.4 ml kg W^− 0.75 d^− 1), Panicum DMI (22.3 ± 2.77 g kg W^− 0.75 d^− 1), total DMI (35.7 ± 2.83 g kg W^− 0.75 d^− 1), and LWG (198 ± 44.6 g d^− 1) not significantly different (P > 0.05). Supplement DMI varied (P < 0.05) from 11.6 g kg W^− 0.75 d^− 1 in Diet 3 to 16.6 g kg W^− 0.75 d^− 1 in Diet 4. In Trial II, 16 pre-weaned local and crossbred calves were involved over 77 d with initial age of calves, Panicum intake, metabolic DMI, and LWG similar (P > 0.05) among crosses. Birthweight varied (P < 0.05) from 17.3 kg for N'Dama × Jersey crosses to 21.2 kg for White Fulani × Brown Swiss crosses. Supplement and total DMI ranged (P < 0.05) from 172 to 483 g d^− 1 for N'Dama × Jersey crosses to 233 and 674 g d^− 1 for non-inseminate or purebred calves, respectively. The LWG in the White Fulani × Brown Swiss and the N'Dama × Jersey calves were respectively 30% and 24% better, though not significantly, than purebred calves. In Trial III, rumen DM degradability characteristics of feeds in three N'Dama steers showed no significant differences (P > 0.05) in slowly degradable fraction (b) and rate of degradation of b (c). Soluble fraction (a), 48-h degradation, potential degradability (PD) and effective degradability (ED) varied significantly (P < 0.05) and were lowest in Panicum, but similar for foliage among the three sweet potato cultivars. Panicum fodder showed improvements in degradation characteristics with supplementation.     

榆林地区马铃薯疮痂病的田间药剂防治

针对榆林地区马铃薯产区疮痂病高发且逐年加重的趋势，通过5种杀菌剂组合处理（70%甲基托布津WP播种期拌种+杀菌剂生长期灌根），以及2种微生物菌肥组合处理（播种期拌种或生长期灌根），探究不同处理对疮痂病的防治效果。结果表明：各处理对疮痂病均有不同程度的防治效果，其中芽孢杆菌复合生物菌剂灌根处理和70%甲基托布津WP拌种+47%春雷王铜灌根处理对疮痂病防治效果最好，防效分别为  67.84%和56.09%；商品薯率及产量均显著高于不施药对照，商品薯率分别增加26.88%和25.80%，产量分别增加62.39%和45.77%。综上可知，芽孢杆菌复合生物菌剂灌根处理和70%甲基托布津WP拌种+47%春雷王铜灌根处理在防治疮痂病及提高马铃薯产量等方面表现良好，具有一定的应用潜力。     

不同小整薯规格和药剂拌种处理对旱作重茬马铃薯生长及产量的影响

以定薯5号为试验材料,在马铃薯重茬地进行田间试验,研究不同小整薯规格和药剂拌种处理对马铃薯生长和产量的影响。结果表明,小整薯播种比种薯切块播种处理出苗期和成熟期提前,株高增加,单株根数、单株主茎数和单株结薯数增多,出苗率、大中薯率和产量提高。与不拌种播种相比,药剂拌种播种处理的株高增高,单株主茎数、匍匐茎数和单株结薯数增多,出苗率、大中薯率和产量提高,用72%农用链霉素0.04kg+滑石粉2kg拌种50kg种薯对马铃薯黑痣病防治效果最好,达到60.1%。     

两种联合固氮菌剂对玉米的拌种试验

用田菁茎瘤固氮根瘤菌与肺炎克氏杆菌分别拌种玉米，结果，玉米分别增产１５３％和１０２０％。每公顷７．５ｋｇ菌剂与每公顷施６００ｋｇ碳酸氢铵增产效果基本相同。     

微量元素水溶肥对大白菜生长和生理特性的影响

本试验采用0.50、0.75、1.00、1.25 g/L四种浓度的微量元素水溶肥对大白菜进行叶面喷施,研究了不同浓度微量元素水溶肥对大白菜生长和生理特性的影响。结果显示,四种浓度微量元素水溶肥料处理的大白菜的植株高度、叶长、叶宽、鲜质量等形态指标均有明显提高,对植株可溶性蛋白含量、维生素C、叶绿素含量影响显著。高浓度处理效果优于低浓度处理,其中,1.00 g/L处理的大白菜叶最长;播后35 d,株高最大;维生素C含量最高,植株硝酸盐的降低效果最佳。以上结果表明,微量元素水溶肥料的叶面喷施促进了大白菜的生长发育,提高了大白菜的品质和风味,其中以1.00 g/L处理的效果最佳。     

湿态发酵蛋白饲料肉牛育肥试验

湿态发酵蛋白饲料是玉米经酵母发酵、提取酒精后,又经益生菌发酵、密封包装的产物,其可溶性好、易消化、易吸收、蛋白质含量高。通过对肉牛进行饲喂试验可知,肉牛食用8kg该饲料,平均每头牛日增重1.81kg,比对照组高0.26kg;平均屠宰率为57.1%,比对照组高3.8%;平均售价为21.35元/kg,比对照组高1.52元/kg;平均每日比对照组多收益6.1元。试验结果表明,肉牛饲喂湿态发酵蛋白饲料增重效果好、屠宰率高,经济效益显著提高。     

樟采穗圃营建技术

对樟采穗圃初步的研究表明:①施肥对樟穗条数量与质量有着极为重要的影响,以3月份施肥,8月份再做同样的处理效果最好,插条质好且量大;②不同定干方式,以30cm促萌明显;③不同时期平茬,最适宜的时间是8月份。     

Light modification in a developing silvopastoral system in the UK: a quantitative analysis

Transmitted photosynthetically active radiation (PAR) was measured in eight-year-old silvopastoral stands at three different locations in the UK by using PAR sensors randomly distributed between four adjacent trees planted in a square pattern. Two densities (100 stems.ha^-1 and 400 stems.ha^-1 were compared. The annual carrying capacity (live weight of the animals that a plot supports) was also recorded as an indirect figure of the overall agricultural production of the system. The silvopastoral plots received less radiation than the agricultural plot without trees, the 400 stems.ha^-1 treatment being more shaded than the 100 stems.ha^-1. Over the measurement period, on some special days, a maximum of 30% of the incoming radiation was intercepted on the 400 stem.ha^-1 treatment with the largest trees. The amount of light intercepted was highly correlated with the type of weather and the leaf area development of the trees: the brighter the day and more expanded the leaf area, the higher was the proportion of radiation intercepted by the tree. However, over the measuring period, a small amount of radiation was intercepted by the tree canopies. As a consequence, no differences were observed in the annual carrying capacity. This revised version was published online in June 2006 with corrections to the Cover Date.     

叶面喷施SOD液肥对小麦生长和产量构成因素的影响

为了进一步研究SOD液肥对小麦生长发育和产量构成因素的影响,试验利用不同浓度SOD液肥在小麦拔节期对其进行叶面喷施试验,稀释浓度分别为100、300、500倍液,以喷施等量清水作对照.结果显示:①喷施SOD液肥能促进小麦光合作用及干物质积累,达到增产效果;②在拔节期叶面喷施3种不同浓度的SOD液肥有不同的肥效,处理2比对照增产19.55％,处理1比对照增产13.13％,处理3比对照增产6.28％.表明叶面喷施SOD液肥是一项简单易行、回报率相对较高的增产措施,在小麦高产高效栽培方面属一项实用技术,有较高的推广应用价值.