论南方红黄壤地区饲草开发利用的几种途径

本文在论述我国南方红黄壤地区的自然特征、社会经济、资源与环境现状的基础上，对如何开发利用该区饲草进行了探讨，指出保护和改善生态环境，积极实行林草结合、种养结合、粮草轮作和发展种草配套养鱼以及调制人工干草制品，是该区丘陵山地发展饲草的有效途径。     

Effect of sewage sludge–coir pith pellets on dry matter yield and trace metal concentration in various plant parts of forage maize

Sewage sludge (SS), a highly heterogeneous semisolid fraction of sewage water (about 1% of the sewage water), contains various amounts of nitrogen (N) and phosphorus (P) as well as trace elements such as cadmium (Cd), lead (Pb), copper (Cu), nickel (Ni) and zinc (Zn) with extremely variable physical and chemical compositions. Application of SS improves soil properties, increases yield and simultaneously increases trace metal content in soil and plants. The difficulty in handling, transporting and applying SS and its adverse effect, especially trace metal content in soil and plant, can be overcome by SS–coir pith pelletization (SSCP) or mixing with sewage sledge–coir pith mixture (SSCM). A study was undertaken to evaluate the prepared SSCM and SSCP (1:1 ratio of SS and coir pith) along with SS on dry matter yield, trace metal content in soil and plant parts. The results showed that increased rates of application of SS or SSCM or SSCP increased the green and dry fodder yield of forage maize. Application of SS as either SSCM or SSCP at 1.2 and 2.4 g pot^?1 significantly reduced the trace metal content diethylene triamine pentaacetic acid (DTPA extractable) in soil and plant parts (leaves steam and root) compared to SS application. Therefore, in order to reduce the bioavailability of trace metal in soil and its uptake by plant, application of SSCM or SSCP at 1.2 or 2.4 g pot^?1 proved to be a better option than SS application.     

Evaluation of Diversity among North American Accessions of False Indigo (Amorpha fruticosa L.) for Forage and Biomass

False indigo (Amorpha fruticosa L.) is a perennial leguminous shrub native to North America. The species could potentially be used for livestock forage, biomass energy, reclamation of degraded environments, or as green manure. Future work with the species will depend upon knowledge of available accessions. Our objectives were to determine (1) the range of diversity among accessions, (2) the correlations among traits across locations, and (3) the distribution of variation among accessions. We studied 21 accessions grown at two locations and a subset of 15 accessions grown at a third location. We measured 47 morphological, agronomic, and phenological traits. All traits were influenced by accession in at least one location (p < 0.05). The mean dry matter (DM) biomass yield of accessions in August ranged from 53 to 1515 g plant⁻¹ and was correlated across locations. False indigo had a high second-year leaf concentration, averaging 660 g kg⁻¹ DM at one location in August. Forage quality of false indigo leaves was high, with average crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF) concentrations in July of 205, 226, and 235 g kg⁻¹, respectively. Accession means of forage quality traits were poorly correlated across locations, indicating that it would be difficult to improve forage quality through selection. Diversity among accessions was often related to geographic origin. The two southern accessions were distinct from all other accessions, indicating that accessions from distant geographic regions will likely contribute valuable diversity to a plant breeding program.     

Photosynthesis and Leaf Area of Brachiaria brizantha in Response to Phosphorus and Zinc Nutrition

Phosphorus (P) and zinc (Zn) are important determinants of plant productivity, particularly in the tropical grasslands of Brazil. Nutrient deficiency is one of the most important factors limiting plant productivity, decreasing photosynthesis efficiency and plant development. The present study investigates in Brachiaria brizantha (Hochst. ex A. Rich.) Stapf. cv. ‘Marandu’: 1) the gas exchange measurements; 2) the total leaf area development; and 3) the dry matter production due to P and Zn nutrition. Plants of B. brizantha cv. ‘Marandu’ were grown in nutrient solution under five rates of P (0.1, 0.6, 1.1, 1.6, and 2.1 mmol L^?1) and five rates of Zn (0.00, 0.75, 1.5, 2.25, and 3.00 μmol L^?1), in a fractioned factorial. Plants were harvested two times. Phosphorus supply increased carbon dioxide (CO₂) assimilation and stomatal conductance, and decreased intercellular CO₂. The interaction P rates x Zn rates were significant for the total leaf area variables and shoot dry matter in the second growth period. The nutrition of P and Zn interfered in the B. brizantha productivity by changing the grass photosynthesis and leaf area.     

The Influence of Row Spacing and Seeding Rate on Seed Yield and Yield Components of Forage Turnip (Brassica rapa L.)

The effects of four row spacings (17.5, 35.0, 52.5 and 70.0 cm) and five seeding rates (50, 100, 200, 400 and 800 viable seeds m^?2) on seed yield and some yield components of forage turnip (Brassica rapa L.) were evaluated under rainfed conditions in Bursa, Turkey in the 1998–1999 and 1999–2000 growing seasons. Plant height, stem diameter, pods/terminal raceme, total pods/plant, seeds/pod and primary branches/plant were measured individually. The number of plants per unit area was counted and the lodging rate of the plots was scored. The seed yield and 1000‐seed weight were also determined. Row spacing and seeding rate significantly affected most yield components measured. The number of plants per unit area increased with increasing seeding rate and decreasing row spacing. Plant height was not greatly influenced by row spacing and seeding rate, but higher seeding rates reduced the number of primary branches and the stem diameter. The number of pods/main stem was affected by row spacing and but not by the seeding rate. Also, the number of seeds per pod was not affected by either the row spacing or the seeding rate. In contrast, the number of pods per plant clearly increased with increasing row spacing, but decreased with increasing seeding rate. The plots seeded at narrow row spacings and at high seeding rates were more sensitive to lodging. Seeding rate had no significant effect on seed yield in both years. Seed yield was similar at all seeding rates, averaging 1151 kg ha^?1. However, row spacing was associated with seed yield. The highest seed yield (1409 kg ha^?1) was obtained for the 35.0‐cm row spacing and 200 seeds m^?2 seeding rate combination without serious lodging problems.     

Chemical Composition and In Vitro Digestibility of Whole-Crop Pea and Pea–Cereal Mixture Silages Grown in South-western Quebec

The objective of this study was to determine the chemical composition and in vitro dry matter (IVDMD) and neutral detergent fibre (IVNDFD) digestibilities of silages made from whole‐crop pea [Pisum sativum L. (PS)], pea–wheat [Triticum aestivum L. (PW)], pea–barley [Hordeum vulgare L. (PB)] and pea–oat [Avena sativa L. (PO)] mixtures harvested 8 weeks (H8) and 10 weeks (H10) after seeding. Forty‐five days after ensiling, all forages were well ensiled as indicated by low pH and low water‐soluble carbohydrate content and high lactic acid concentration. Regardless of forage type, crude protein (CP) and IVNDFD were higher while starch and acid detergent lignin were lower in H8 than H10. However, harvest date had no effect on neutral (NDF) and acid (ADF) detergent fibre of the silages. Within each harvest date, CP was higher while NDF was lower for PS than pea–cereal silages. Differences in CP and fibre fractions between the pea–cereal mixture silages were not consistent for the two harvest dates. The IVDMD of PS was higher than that of the three pea–cereal mixture silages in H8 but was only higher than that of PB in H10. For the pea–cereal mixtures, IVDMD was higher for PO than PB and PW in H8 and was higher for PB than PW in H10. It was concluded that silage from pea monoculture had similar forage yields and a generally higher nutritive value than silages from pea–cereal mixtures.     

HJJ-80型卧式饲料搅拌机的设计

随着畜牧业的发展,对饲料数量及质量有了更进一步的需求。搅拌机是饲料加工中的关键设备，因此搅拌机的正确设计对生产饲料的质量及经济性有着重要影响。为此，按照饲料配方的要求，根据提出的主要技术参数，确定了整机的结构尺寸及配套动力，设计和试制了饲料搅拌机。     

北大营示范场黑麦草引种与品比试验研究

利用1998年2－11月在云南省北大营示范场引种的10个黑麦草品种的观测资料，统计分析了在高、中、低3种施肥水平下黑麦草的累计产量、月平均产量及其生长速度的变化规律，研究了影响产量的主导因子及其监测模型。结果表明，在10个品种中，伯生（Bison Intermdiate）及安巴瑟（Embassy）具有良好的生产性能。黑麦草产量主要受气候、土壤肥力及品种等因素的影响，其中测草盘高度、降水量、蒸发量、日照时数和牧草生长天数等5个因子，可以较好地模拟、评估黑麦草产量的变化动态。     

蛋氨酸螯合铁对断奶仔猪生产性能的影响

本试验选用36头35日龄体重7.7kg左右的杜长大三元杂交商品代断奶仔猪,随机分为试验组和对照组,每组18头,公母各半。试验组饲料中添加0.04%的蛋氨酸铁螯合物,对照组饲料中不添加蛋氨酸铁螯合物。经过30d的饲养试验,结果表明:(1)试验组的日增重比对照组多增重77g,提高了25.4%,差异极显著(P<0.01);试验组的平均采食量比对照组增加92g,提高了19.5%;试验组的料重比比对照组降低4.5%。(2)经济效益显著:试验组仔猪增重1Kg获得的毛利润比对照组多0.12元,试验期间每头小猪比对照组多盈利16.87元。     

Use of regrowth for forage in crops of timothy (Phleum pratense L.) cv. Grindstad grown for seed in Norway

Six experiments were carried out in two climatically different regions in south‐east Norway in order to compare different procedures for autumn management and use of regrowth in seed crops of timothy (Phleum pratense L.) cv. Grindstad. The experiments were laid out after seed harvest in mid‐August in crops with a stubble height of 5 cm (two experiments) or 12–15 cm (four experiments). Cutting to 5 cm on 15 September or 15 October, with or without an application of 50 kg N ha^?1 immediately after seed harvest, and with or without an additional application of 30 kg N ha^?1 after cutting, were compared with an uncut and unfertilized control treatment. As a main effect,autumn cutting increased seed yield in the subsequent year in only one experiment; this was laid out in a 13 cm stubble on a fertile soil near the coast. In the remaining five experiments seed yields were unaffected byautumn management regardless of climate or stubble height. Autumn cutting and N application increased the number of seedheads in two experiments, but this was offset by a drop in other seed yield components. On average for two cutting dates and for plots receiving an application of 50 kg N ha^?1 after seed harvest, the dry matter (DM) was 1430 kg ha^?1 on an inland site with 12–15 cm stubble, 1400 kg ha^?1 on a coastal site with 5 cm stubble and 2460 kg ha^?1 for two coastal sites with 12–15 cm stubble. Whereas forage yield and quality were fairly stable from the first to the second cut at the inland site, the yield of DM increased, but the crude protein and energy concentrations decreased from 15 September to 15 October at the coastal sites. It is concluded that the stubble and regrowth in seed crops of timothy cv. Grindstad can be harvested for forage without any effect on seed yield in the next year.