低蛋白日粮对生长猪舍NH3和H2S质量浓度及猪生产性能的影响

将48头平均体重约27 kg的杜×(长×大)三元杂交生长猪根据体重和性别分成4组,饲喂4种不同蛋白质水平日粮,3种试验日粮根据理想氨基酸模式配制.试验结果表明:①4组日增重与料重比差异不显著(P>0.05).15%粗蛋白组生长速度最快,14%粗蛋白组经济性能最好,平均增重利润比17%粗蛋白组多0.41元/kg.②14%、13%粗蛋白组血清尿素氮分别显著(P<0.05)、极显著(P<0.01)低于17%粗蛋白组.③4组猪舍期中、期末氨气质量浓度,14%、13%粗蛋白组分别显著(P<0.05)、极显著(P<0.01)低于17%粗蛋白组,各组硫化氢质量浓度无显著差异(P>0.05).     

近50年长三角地区季节的气候变化特征

根据长三角地区31个站点1961-2010年逐日气温资料,按照国家标准进行季节划分,在研究四季长度和起始时间变化特征的基础上,利用Mann-Kendall检验、等值线等方法对季节的时间变化趋势和空间分布特征进行研究。结果表明,时间变化上,长三角地区夏季长度有极显著的增加趋势(P0.01),春、夏两季的起始日期有显著的提前趋势(P0.01和P0.05)。空间分布上,春、秋季节长度由内陆向沿海增加,夏季长度由北向南递增,冬季长度由北向南递减。四季长度变化趋势的空间结构为:春、夏季以延长为主,秋、冬季主要表现为缩短,其中夏季长度的延长最为显著(P0.01)。四季起始时间空间分布为:春、夏季南部入季早,秋、冬季北部入季早;起始时间变化趋势的空间结构为:春、夏季为一致的提早趋势;秋、冬季以延后为主。     

应用卫星遥感技术对水稻长穗期长势监测的研究

本项研究通过卫星遥感技术,实现对水稻长穗期长势的遥感监测,并针对遥感信息开展调优措施,实现水稻稳产、高产的目的。通过试验研究,利用卫星遥感监测水稻长穗期后四叶长势,具备全面、准确的优势,准确度达80%,实现大范围监测,完成由"点"状数据向"面"的转变,并且依据遥感信息实施调优栽培技术,调整群体结构,这对于指导大规模水稻生产具有一定意义。     

论我国南方林区草珊瑚的人工栽培

在介绍草珊瑚之价值的基础上,论述了我国南方林区人工栽培草珊瑚的意义和可行性.     

冬春季节遮阴处理对香蕉假植苗生长的影响

冬季 (12～ 1月 )、春季 (3～ 4月 ) ,将从培养瓶中移出的香蕉组培苗置于大棚内 ,在 4种遮阴水平下进行假植炼苗 ,光照条件分别为 10 0 % (S10 0 ) ,33% (S33) ,10 % (S10 ) ,3 % (S3)。结果表明 ,不同光照强度下 ,香蕉苗的苗高、基径、叶长、叶宽、叶片数、叶面积、总根数和长根数都存在显著差异 ,但不同的性状对光照强度的反应不同。冬季有利于根系的生长 ,春季则更有利于地上部性状的生长。冬季和春季都以S33光照处理为最优 ,即适度遮阴有利于香蕉假植苗的生长发育。但春季各性状对遮阴水平适应的范围比冬季更宽 ,并且各性状在不同的季节对同一遮阴水平的反应也不相同 ,这表明光照强度与季节之间存在互作效应     

Influence of cutting frequency on the morphology and the C and N reserve status of two cultivars of white clover (Trifolium repens L.)

The influence of cutting frequency was studied on white clover (Trifolium repens L.) cultivars (giant-Aran and dwarf-Rivendel) during two experiments set up under field conditions. Clover morphological and biochemical characteristics were measured prior to regrowth in response to various cutting interval treatments (1, 2, 3, 6 and 8 weeks of regrowth between two successive defoliations). The morphology of the aerial parts of the plant was described through the residual leaf area (RLA), the number of total growing points (TGP), stolon length and stolon and root dry matter productions per unit of cultivated area, as well as stolon dry weight per unit length. C and N reserve status was assessed by starch and vegetative storage proteins (VSP) concentration and amount measurements. Cutting frequency largely influenced the different variables. RLA and TGP increased in response to frequent cuttings while all other morphological and biochemical parameters decreased, with the exception of the soluble protein concentrations and protein amounts. Nevertheless, a significant difference in morphology and C and N reserve accumulation was shown between the two clover cultivars. In spite of a few number of leaves and growing points, the giant cultivar Aran showed higher C and N reserves, compared with the dwarf type Rivendel. However, the genetic expression of these differences was tightly linked to the cutting frequency applied to the sward, and was at its maximum in response to the most frequent treatments. Subjected to severe cuttings, both genotypes showed an increase in RLA and TGP, the greater effect of the treatment was obtained with the dwarf-type Rivendel. Frequent defoliations strongly reduced organic reserves but the cutting-induced decreases observed in starch and VSP contents were similar for each cultivar. Overall results confirmed that the morphological development of clover, partly defined by genetic performance, should also be controlled by cutting frequency, and highlighted a tight relationship between morphogenesis, reserve accumulation and sward management. Results are also discussed in terms of the use of C and N reserve contents as a further characterisation of white clover cultivars.     

Phenological Development–Yield Relationships in Dry Pea in Semiarid Mediterranean Conditions

Dry pea (Pisum sativum L.) growers in the semiarid Mediterranean region require cultivars that are both early maturing and high yielding. However, negative relationships between these two characteristics limit their simultaneous improvement. A better understanding of the relative importance of the developmental stages in determining yield would assist in pea improvement. Sixteen dry pea cultivars were grown for 2 years under semiarid Mediterranean conditions (Maru, north Jordan) in order to see if differences in growing degree days (GDD) to flowering and GDD from planting to physiological maturity exist and to study their relationships with seed yield. Seed yield was negatively correlated with GDD to maturity, but not significantly correlated with GDD to flowering. Increasing GDD to flowering resulted in higher seed yield, while increasing seed fill duration had little effect. Rapid seed fill rate was positively correlated with seed weight and negatively correlated with seed fill duration. These results indicate that Mediterranean-adapted cultivars would have preflowering periods lasting as long as possible, followed by short seedfill periods. Simultaneous selection for early maturity and a relatively long time to flowering is recommended for the development of early-maturing, high-yielding cultivars adapted to semiarid Mediterranean environments.     

35～60kg生长猪可消化氨基酸需要量研究

选用大白×长白杂种猪 6 0头 ,试验采用单因子试验设计 ,随机分为 5个处理 ,每个处理 4个重复 (圈 ) ,每个重复3头猪。 5个处理饲粮DLys水平分别为 0 .33%、0 .46 %、0 .5 8%、0 .71%和 0 .83% ,相应的CP分别为 8.6 1%、11.33%、14.0 6 %、16 .6 7%、19.2 9%。饲粮等能 (13.6 4MJDE/kg) ,等氨基酸模式 ,其氨基酸模式DLys:D -SAA :DThr:DTrp为 10 0 6 0 6 1 18。试猪始重 35 .2± 3.5 8kg ,末重 5 9.5 7± 6 .37kg。试验除考察生产性能外 ,还同时测定了氨基酸的回肠表观消化率。结果表明 :生长猪的ADG(Y1)、饲料转化率 (Y2 )均随饲粮DLys水平 (X)的增加呈显著的二次曲线变化。当DLys水平分别为 0 .6 4%和 0 .6 6 %时 ,ADG和饲料转化率分别达到极大值 (76 2 .32g)、极高值 (2 .85 )。由此可推算 ,35～6 0kg生长猪达最佳生产性能的DLys、D -SAA、DThr、DTrp和CP需要量分别为 0 .6 5 %、0 .39%、0 .40 %、0 .12 %、15 .43% ,饲粮DLys/DE之比为 0 .48g/MJ。     

酶制剂对饲喂不同蛋白和能量水平日粮生长猪生产性能和养分消化率的影响

选用体重约26千克的杜长大三元杂交猪100头,随机分成四组。分别饲喂正对照基础日粮、负对照基础日粮、正对照基础日粮 0.075%酶制剂、负对照基础日粮 0.075%酶制剂,研究常规蛋白和能量水平以及蛋白水平降低一个百分点、能量降低0.5MJ/kg的条件下,酶制剂对生长猪生产性能和日粮养分消化率的影响。结果表明:正对照 酶组的平均日增重(ADG)和饲料转化率(FCR)比正对照组提高了19.3%和19.2%;干物质(DM)、粗蛋白(CP)、粗脂肪(EE)和能量(DE)的消化率分别比正对照组提高了2.3%、1.9%、7.2%和1.5%;负对照 酶组的平均日增重(ADG)和饲料转化率(FCR)比正、负对照组分别提高了15.6%和18.9%、13.1%和12.5%;干物质(DM)和能量(DE)消化率比负对照组提高了1.5%和3.3%;正负对照 酶明显改善了养殖经济效益。     

Wetting agent effect on physical properties of new and reused rockwool and coconut coir waste

Wettability of growing medium in horticulture is an important practical factor of this industry. With a proper choice and a right application, wetting agent in the nutrient solution would improve wettability and some other physical properties of growing media. The aim of this study was to evaluate the effects on some physical properties of new and reused rockwool and coconut coir dust substrates with different doses of wetting agent (2, 10, 20, 100, 200, 1000, 2000, 10,000 and 20,000 mg L⁻¹) applied to the nutrient solution and their effects measured by using bioassays. The wetting agent was ether poly-ethylene-glycol nonil-phenol with 20% (w/v) as an active ingredient of a non-ionic surfactant. Bioassay results showed differences among species. For this, the method can be suggested as a good tool to be utilized through fertigation in soilless crops; however, other studies should be proposed for each species in particular. Except to the 2 mg L⁻¹ wetting agent content in reused coir waste, the total water-holding capacity increased with the wetting agent. With 2 mg L⁻¹ wetting agent content there was an important and significant increase the easily available water (over 600%) in both substrates (including the reused ones), while higher doses show no significant differences. The effect of adjuvants added through fertigation is directly dependant on the substrate type evaluated. The substrate reutilized after one crop, reduces the air capacity and increases the easily available water and total water-holding capacity. 2 mg L⁻¹ is the wetting agent concentration more adequate in coir waste and rockwool.