CO2 Enrichment Effects on Forage and Grain Nitrogen Content of Pasture and Cereal Plants

SUMMARY

Increasing atmospheric CO₂ concentrations [CO₂] have the potential to enhance growth and yield of agricultural plants. Con-comitantly plants grown under high [CO₂] show significant changes of the chemical composition of their foliage and of other plant parts. Particularly, high [CO₂] result in a decrease of plant nitrogen (N) concentration, which may have serious consequences for crop quality. This presentation summarizes the results of a variety of CO₂ enrichment studies with pasture plants (Lolium spp., Trifolium repens) and cereal species (Triticum aestivum, Hordeum vulgare) which were conducted at our laboratory under different growth and CO₂ exposure conditions ranging from controlled environment studies to investigations under free air carbon dioxide enrichment (FACE). With the exception of clover in all experiments a CO₂-induced decline of forage and grain N concentration was observed. The magnitude of this reduction differed between species, cultivars, management conditions (N fertilization) and CO₂ exposure conditions. No unambiguous evidence was obtained whether N fertilization can contribute to meet the quality requirements for cereals and grass monocultures with respect to tissue N concentrations in a future high-CO₂ world. As shown in the FACE experiments current application rates of N fertilizers are inadequate to achieve quality standards.     

威宁芜菁甘蓝牧草生产技术规程

为规范威宁芜菁甘蓝牧草生产技术,提高牧草产量和质量,针对贵州省威宁芜菁甘蓝牧草生产的现实,依据国家、行业标准,对威宁芜菁甘蓝牧草生产的环境条件、栽培和利用技术等提出了具体要求和规定,对贵州乃至长江中上游海拔800～3 000m及类似地区威宁芜菁甘蓝牧草生产具有指导意义.本技术规程于2013年4月15日通过贵州省质量技术监督局组织的专家审定,2013年5月20日发布,2013年6月20日实施.     

Production of plantlets from tissue cultures of Lotononis,a southern African veld legume1

Abstract

A simple procedure is described for the production of large numbers of rooted plantlets from callus cultures of Lotononis bainesii Baker. Highest frequency of shoots was obtained from somatic embryos formed in initiation cultures on Murashige & Skoog medium plus 1 mg/l benzylaminopurine plus 1 mg/l naphthaleneacetic acid. The somatic embryos from these initiation cultures were transferred to media containing 0,5,10 or 20 mg/l isopentenyladenine or 0,1 or 5,0 mg/l kinetin (1,8 to 3,1 shoots per culture) where they re‐callused and produced shoots. All shoots obtained from the cultures on media containing 0,5, 10 or 20 mg/l isopentenyladenine or 0,1 mg/l kinetin were rooted; 35 % of shoots from the cultures on medium containing 5,0 mg/l kinetin were rooted. Rooting of unrooted shoots from other treatments was readily induced on medium containing 0,1 mg/l indoleaceticacid.     

刈割时期对昭苏马场人工割草地产量和品质的影响

分别于2013年7月上中旬和8月上中旬对新疆维吾尔自治区伊犁哈萨克自治州昭苏马场人工割草地进行刈割,并进行了产草量测定和牧草品质的比较分析。结果表明,刈割时期对建植第3年和第7年割草地的鲜草和干草产量无明显影响;8月上中旬刈割牧草的粗蛋白（CP）含量与7月上中旬刈割牧草相比显著降低（P〈0．05）;刈割牧草中。豆科牧草的比例无明显变化,但8月上中旬刈割牧草的叶茎比显著降低（P〈0．01）;在8月上中旬刈割的牧草中,中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量有不同程度的增加（P〈0．05）。由试验可知,昭苏马场的合理割草时间以7月上中旬为宜,此时牧草的产量和质量较佳。     

Response of Forage Chicory Seedlings to Available Soil Phosphorus in Two Soils in a Controlled Environment

Poor phosphorus (P) fertility is a problem limiting productivity on unimproved Appalachian soils and has been implicated in poor palatability of forage chicory (Cichorium intybus L.). Three cultivars were grown in a greenhouse at varying soil P levels in Gilpin and Hagerstown silt loam soils and harvested 48 and 77 days after planting. In Gilpin soil, available soil P (ASP) was positively associated with dry shoot mass, leaf mass, leaf area, and leaves per plant and negatively associated with specific leaf area. In Hagerstown soil, ASP was positively associated only with only dry shoot and leaf mass. At equivalent ASP levels, dry shoot and leaf mass, leaf area, and shoot concentrations of P, potassium, calcium, and magnesium were always greater in Hagerstown than Gilpin soil, whereas specific leaf area was less. Equalization of ASP concentration and environmental conditions did not eliminate growth-limiting differences between Gilpin and Hagerstown soils for chicory.     

The Digestion of Guizhou White Goat on the Four Forages and its Enlightenment on Rocky Desertification Control

In order to solve the problem of the lack of nutritional value parameter of White goats,better understand the metabolism rule in White goats fed pasture,and provide a reference to the optimization allocation of grassland nutrition and healthful aquaculture of white goats in rocky desertification control in Guizhou province.Six healthy Guizhou White goats with rumen cannulas were selected,taking Medicago sativa,Trifolium repens,Lolium perenne and Bromus catharticus four kinds of forages in Karst areas as the research object,nylon bag technique was used to determine the degradability dynamics and degradation model parameters of DM,CP,NDF and ADF.The results showed that among four kinds of forages at 72 h,the highest degradation rate and effective degradability rate of DM was white clover (P<0.05),the decrease in the sequence were alfalfa,rescuegrass and perennial ryegrass;The highest degradation rate and effective degradability rate of CP was alfalfa (P<0.05),followed by were white clover,rescuegrass and perennial ryegrass;While the rescuegrass and alfalfa showed the best for NDF and ADF,white clover and perennial ryegrass came second.The analysis showed that the four kinds of nutrients were absorbed well by White goat,and the alfalfa performance was the most superior which could promote the development of grassland animal husbandry in Karst areas.     

元阳县少数民族地区饲用植物种质资源调查及利用研究

对元阳县少数民族地区4个乡(镇)的饲用植物种质资源进行调查,调查涉及饲草饲料植物和野生牧草种质资源的种类、种植现状、利用方式、适口性等方面。共调查记录人工种植的饲草饲料植物17份,分属12科16属17个种;当地家畜主要采食的野生牧草种质116份,分属25科88属116个种。元阳县饲草饲料植物和野生牧草资源十分丰富,丰富的饲草料资源为当地发展草食家畜养殖奠定了良好的基础。     

Evaluation seedling biomass and its components as selection criteria for improving salt tolerance in Buffel grass genotypes

Damage produced by salt stress (300 mm NaCl) under hydroponic greenhouse conditions in seedlings of eight Buffel grass (Cenchrus ciliaris L. Syn. Pennisetum ciliare Link) genotypes was estimated through different component characters of total fresh weight damage (DTFW). Coefficient of genetic determination (CGD) was estimated for each character as well as their direct and indirect contribution to damage to total fresh weight, considered as biomass production loss. Americana and Biloela were the most salt‐tolerant cultivars, whereas sexual line and Texas 4464 were the genotypes most susceptible to salt stress. Damage to fresh weight of aerial part (DFWA) was the only component with a direct effect on DTFW and with a high CGD. Therefore, DFWA could be used in breeding programmes as an indirect selection criterion for tolerance and better productivity.