水分对硝酸磷肥中氮的扩散及其肥效的影响

国产硝酸磷肥含氮27%,磷13.5%。所含速效氮中硝态氮均占一半。研究麦田不同水分对硝酸磷肥中硝态氮在土壤中扩散结果显示,硝态氮在土壤中下移深度与土壤湿润峰的深度基本一致,在小麦越冬期有表聚现象。当灌水量为田间持水量时,硝态氮移动深度为40～50cm,是在主要根系活动层内,这对小麦吸收有利,不会产生氮的流失。等氮磷条件下,硝酸磷肥与磷铵加尿素在北方地区有同样肥效。     

陇南红芪无公害栽培技术

从栽培地的选择、采种与种子处理、育苗、移栽、大田管理、采挖与粗加工等方面介绍了陇南市红芪无公害栽培技术。     

"双链型"草-鹅-稻生态农业模式高产高效配套技术

提出了“双链型”单-鹅-稻生态农业模式，总结了稻田套种牧草的方法和田间管理技术，探讨了种草与养鹅在时间上的相互衔接，以提高牧草的产量和利用率，进行了稻田套种牧草养鹅与种植小麦的比较效益分析。该配套技术的实施，为当前开展农业结构调整开辟了一条新路。     

Correlated responses from selection for income minus food cost in pullets on traits in older hens

1. After 5 generations of selection on income minus food cost between 21 and 40 weeks of age (SECR), a correlated genetic improvement of 14.5% and 16.3% of the base population mean could be observed for income minus food cost between 41 and 60 weeks (IF60) in two lines of laying hens. The total responses up to 60 weeks amounted to 17.2% and 17.3% of the base population mean. A heritability of 0.30 for IF60 and a genetic correlation of 0.61 between SECR and IF60 were estimated.

2. The correlated relative genetic responses for 5 traits of the period between 41 and 60 weeks of age for the two lines were: 4.3% and 5.2% in egg number, 5.8% and 7.4% in egg weight, 8.4% and 10.8% in egg mass, ‐2.7% and ‐0.6% in body weight at 60 weeks, and ‐5.2% and ‐6.3% in food efficiency.

3. The estimated heritabilities of these 5 traits from the whole data set were 0.36, 0.75, 0.34, 0.71 and 0.17. The estimated genetic correlations between SECR and the same 5 traits were 0.30, 0.46, 0.61, ‐0.22 and ‐0.49.

4. A high genetic correlation of income minus food cost with egg weight and a low one with egg number were found in pullets, but the relationships were reversed in older hens.     

Effects of cultivar,pelleting and enzyme addition on nutritive value of barley in poultry diets

1. The effect of pelleting process and Trichoderma viride enzymes (TVE) addition on apparent metabolisable energy, corrected for nitrogen balance (AMEn) and on productive value of practical diets containing 40 and 45% of three different barley cultivars and one wheat were studied in poultry.

2. The effect of the pelleting process on AMEn was inconsistent and was dependent on the cereal included and the addition of enzyme.

3. The growth trial showed a significant effect of enzyme addition to pelleted diets over the whole growth period (0 to 42 d). Addition of TVE improved weight gain and food efficiency by 1.3% and 2.9%, respectively and decreased food intake by 1.6% between 0 and 22 d. In the finisher period (23 to 42 d) TVE improved efficiency by 2.8% and reduced food intake by 2.9%.

4. The incidence of sticky droppings was related to the viscosity of barley used, and enzyme supplementation reduced it. Both pelleting and enzyme addition increased dry matter content of excreta.

5. At the end of the experiment, 14 animals per treatment were slaughtered and carcass yield, viscera weight and abdominal fat were determined.     

光敏核不育水稻选育与利用的几个问题讨论

对现有光敏核不育材料进行了分类,分为４种遗传类型;其中,温光弱感到光敏核不育系是最为理 想的遗传工具,并就其选育途径和选择“粳不籼恢”繁殖制种技术体系进行了论证．     

Rapeseed meal and egg taint: Treatment of rapeseed meal to reduce tainting potential

1. Treatment of rapeseed meal with calcium hydroxide suspension decreased the sinapine content by up to 90%. Smaller decreases were obtained by autolysis, steaming and treatment with ammonia.

2. When this treated meal was fed to susceptible ("tainting") hens the concentration of trimethylamine in the eggs was decreased to much less than that required to cause taint.     

Effect of injecting amino acids into the egg on embryonic and subsequent growth in the domestic fowl

1. The growing embryo uses about 1% of the total protein available in the egg during the first week of incubation.

2. Injecting the growing embryo with amino acids equivalent to the amount of protein used resulted in higher weight of chicks at all stages up to 56 d.     

The use of air‐coolers in broiler houses under subtropical conditions in Iraq

1. Under summer conditions in north Iraq, 2 000 chicks were reared for 56 d in two broiler houses. One house was provided with two air‐coolers. The birds were housed at densities of eight to 16 birds/m².

2. Differences in weight gain between birds in cooled and uncooled houses ranged from 101.5 g at eight birds/m² to 385 g at 16 birds/m². Food consumption increased gradually with increasing bird density. Food conversion efficiency, meat yield and carcass conformation were much better in the cooled house than under conventional conditions.

3. The financial return/m² ranged from 2.30 to 4.51 ID¹ in the cooled house, compared with 2.01 to 2.77 ID in the uncooled house at different floor densities.     

Rapeseed Meal and egg taint

1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine.

2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.