整地筑埂两用机传动系统的设计

为了提高水稻种植机械化的程度,针对其生产过程中的整地筑埂作业工序,设计了一种稻田生产用整地筑埂两用机的传动系统,该传动系统主要由变速箱、传动轴、链传动系统、两个旋耕集土器半轴、离合器、轴承等关键部件组成;采用轮式拖拉机为动力,实现了一次进地,可同时完成整地和筑埂两种作业。田间试验表明,该传动系统设计合理、性能稳定、技术先进,为水稻生产过程全程机械化提供了技术支持。     

Using drainage systems for supplementary irrigation

The use of drainage systems for supplementary irrigation is widespread in The Netherlands. One of the operating policies is to raise the surface water level during the growing season in order to reduce drainage (water conservation) or to create subsurface irrigation. This type of operation is based on practical experience, which can be far from optimal.To obtain better founded operational water management rules a total soil water/surface water model was built. In a case study the effects of using the drainage system in a dual-purpose manner on the arable crop production were simulated with the model. Also, the operational rules for managing this type of dual-purpose drainage systems were derived.The average annual simulated increase in crop transpiration due to water conservation and water supply for subsurface irrigation are 6.0 and 5.4 mm.y^–1, respectively. This is equivalent with 520 × 10³ and 460 × 10³ Dfl.y^–1 for the pilot region (2 Dfl 1 US $). The corresponding investments and operational costs are 600 × 10³ Dfl and 9 × 10³ Dfl.y^–1 for water conservation and 3200 × 10³ Dfl and 128 × 10³ Dfl.y^–1 for subsurface irrigation. Hence, water conservation is economically very profitable, whereas subsurface irrigation is less attractive.Comparing the management according to the model with current practice in a water-board during 1983 and 1986 learned that benefits can increase with some 50 and 500 Dfl per ha per year, respectively.     

甜高粱育种思路探讨

甜高粱生物产量高,含糖量高,乙醇转化率高,抗逆性强,是能源作物,对其合理开发利用,对我国粮食安全、能源安全具有重大意义。我国甜高粱育种水平落后,现有品种不能适应生产发展的需要。创新育种思路,可从选育粮糖兼用型品种和自交不结实的品种方面进行甜高粱品种选育。     

稻麦两用螺旋舀种式排种器排种性能试验

设计了一种稻麦两用螺旋舀种式排种器,确定了该排种器关键部件的结构和参数;运用Design-Expert软件进行数据分析,得到最优参数组合,采用响应面试验方案,进行台架验证试验。结果显示:播种水稻时,在转速为45 r/min、倾斜角度为3°、出种孔长度为9 mm情况下的合格率为78.20%,重播率为3.71%,空穴率为1%,穴距合格率为97.93%,穴距变异系数为16.17%;播种小麦时,在转速为60 r/min、倾斜角度为1°、出种孔长度为9 mm,此组合下的合格率为93.37%,重播率为3.44%,空穴率为3.19%,穴距合格率为93.60%,穴距变异系数为25.50%。     

Early-maturing dual-purpose sorghums: Agronomic trait variation and covariation among landraces

Landrace cultivars represent potentially valuable source material for breeding dual-purpose (grain and stover) sorghums. To characterize the genetic variation and interrelationships for major agronomic traits among potential dual-purpose sorghum landraces, 74 accessions, primarily from Southern Africa, the Sudan, and India, were evaluated in five environments at Patancheru, India. These environments, at 17°N with 520-540 mm rainfall during the growing season, are representative of the major sorghum-growing areas in India and the Sudanian Zone of Western and Central Africa. Significant genetic variation and high heritabilities (P = 0.01, h²= 0.63-0.92) were observed for seedling vigour, grain and stover yields, growth rate and harvest index. Time to flower was correlated with stover yield (r = 0.48, P = 0.01) and an index (I_ev) of total economic value (r = 0.44, P = 0.01) but not with grain yield (r = 0.22, P = 0.05). Grain and stover yields varied independently (r = 0.22, P = 0.05) and were similarly related to I_ev, values (r = 0.79 and r = 0.77 (P = 0.01), respectively). The 13 landraces with the highest I_ev values (adjusted for maturity) had above-average growth rates and harvest indices that ranged from 20 to 38%. Landraces from Botswana and India were more highly represented in the high I_ev set than in the full set of accessions.     

农村户养条件下四川乳肉兼用牛的繁殖性能研究

调查结果表明,四川乳肉兼用母牛的初配年龄在16～24月龄之间,4.5周岁达到成年体尺体重.发情和产犊以9～12自然月为最高,其次为1～4月.牛群结构为成年母牛占42.98%,1.5～4.0岁青年母牛占55.67%,1周岁及以下小母牛1.43%.在所调查1 076头繁殖母牛的2 157个胎次中,共产犊牛2 162头,其中产公犊占50.97%,平均初生重为31.56kg;产母犊占49.03%,平均初生重为29.61 kg;公母比为1.04:1;不同犊牛性别间,公、母牛怀孕期没有明显的差异.产犊间隔平均为381.48天;难产率为0.28%,双胎率为0.28%,犊牛成活率为99.25%.群体第一情期受胎率为33.75%.     

水稻两用核不育系育性转换与温度的相关分析

在贵阳对8个籼型水稻两用核不育系进行了间期为10－15d的分期播种，以套袋自交结实性作为育性考查指标，结果所有核不育系都有稳定不育期和可育或部分可育期表现，且育性转换明显。稳定不育期的长短因不育系不同而有差异，范围在5－33d。自交结实率与日平均气温之间的相关性表明，所有不育系都在幼穗发育的一定阶段内对温度表现敏感，大多数不育系的温度敏感时期在抽前7－24d，培矮64S在抽穗前17－30d。不同不育基因供体来源的不育系对温度敏感时期和持续时间长短存在着差异，同一不育基因供体来源的不同不育系之间，其育性对温度敏感时期和持续时间长短也不相同。     

平凉市16个粮饲兼用型玉米杂交种丰产稳定性分析

引入粮饲兼用型玉米杂交种16个,以中单2号为对照进行试验。结果表明,不同杂交种在不同环境条件下产量稳定性有较大差异。沈单10号(V1)高产稳产,是个较理想的杂交品种,可在本区大面积种植。     

水稻温敏不育系育性鉴定及繁种水温处理系统的设计和应用

水稻温敏不育系育性敏感期处于某种温度条件下表现雄性不育，与父本可配制杂交种；处于另一温度条件下则可育，能自交繁殖种子。使不育过渡到可育的育性转换温度决定着两系法杂交稻制种风险的大小。因此，确定水稻温敏不育系的育性转换温度，筛选导致不育起点温度低的温敏不育系已成为水稻两系法育种的技术关键。本研究的处理系统利用空调机制冷、加热，温控仪自动控温，水温在17～30℃之间可调。水温控制池与植株处理池中的水不断循环，从而达到植株处理池中的水温长期稳定，保持在研究所需要的范围内，完全能满足温敏不育系育性鉴定与繁种的要求     

谷秆两用水稻202对氮肥的吸收利用

应用~(15)N-尿素研究了谷秆两用水稻202对肥料氮素的吸收利用。结果表明,在施等量尿素的条件下,对照稻308与两用稻202的稻谷性状相似,但202稻草含N量比308(CK)提高37.57％。不同时期施肥,肥料氮在谷、草中的分配率不同,308遵循常规稻的分配规律,而202水稻则有自己的特性,即早期追肥大部分分布于稻穗中,较迟施肥大部分分布于茎、叶中。应用~(15)N标记稻草研究其利用价值,202草粉饲料被草鱼和白鼠的消化率比308草粉(CK)提高13.6％和16.5％,机体的~(15)N回收率比CK提高9.6％和6.0％;202稻草栽培平菇,~(15)N回收率比CK提高19.1％,202稻草有较好的综合利用价值。