A COMPARISON OF RUNOFF QUALITY EFFECTS OF ORGANIC AND INORGANIC FERTILIZERS APPLIED TO FESCUEGRASS PLOTS1

ABSTRACT: Application of fertilizer can degrade quality of runoff, particularly during the first post-application, runoff-producing storm. This experiment assessed and compared runoff quality impacts of organic and inorganic fertilizer application for a single simulated storm occurring seven days following application. The organic fertilizers used were poultry (Gallus gallus domesticus) litter, poultry manure, and swine (Sus scrofa domesticus) manure. All fertilizers were applied at an application rate of 217.6 kg N/ha. Simulated rainfall was applied at 50 mm/h for an average duration of 0.8 h. Runoff samples were collected, composited, and analyzed for nitrate N (NO₃-N), ammonia N (NH₃-N), total Kjeldahl N (TKN), ortho-P (PO₄-P), total P (TP), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliforms (FC), and fecal streptococci (FS). Application of the fertilizers did not alter the hydrologic characteristics of the receiving plots relative to the control plots. Concentrations of fertilizer constituents were almost always greater from treated than from control plots and were usually much greater. Flow-weighted mean concentrations of NH₃-N, PO₄-P, and TP were highest for the inorganic fertilizer treatment (42.0, 26.6, and 27.9 mg/L, respectively). Runoff COD and TSS concentrations were greatest for the poultry litter treatment. Concentrations of FC and FS were greater for fertilized than for control plots with no differences among fertilized plots, but FC concentrations for all treatments were in excess of Arkansas' primary and secondary contact standards. Mass losses of fertilizer constituents were low (≤ 3 kg/ha) and were small proportions (≤ 3 percent) of amounts applied.     

MEASURING THE CONTRIBUTION OF LAND AND WATER TO AGRICULTURE1

ABSTRACT Irrigated land outproduces dryland agriculture, especially in the western United States. Many valuable crops could not be grown without irrigation. A paucity of yield data does not allow direct measurement of the contribution from irrigated crop agriculture, nor does it allow evaluation of the contributions from livestock which are dependent upon irrigated feed. Regression results indicate that 80 percent of Idaho farm income is associated with irrigation, and that 75 percent of the farm income in the 17 western states is associated with irrigation. For the United States as a whole, results indicate that 13.7 percent of the total cropland (irrigated land) produced 41.3 percent of all cash receipts from farming in 1978. If 14 percent of the land can produce 40 percent of the value of production, can 35 percent of our land produce all our food and fiber needs? Such an allegation has several implications in terms of the adequacy of our land and water resources. It also emphasizes the role of technology in future resource use and production.     

Ethics and farm animal welfare

In this paper the authors argue that ethical considerations are relevant for evaluating animal production systems and that in consequence agrologists should seriously consider the arguments of animal welfare supporters. Furthermore, the authors point out the ethical basis for some (though not all) of the conclusions proposed by supporters of animal welfare. In consequence it is necessary to determine the nature of animal welfare and methods of evaluating the welfare of animals and to recognize when production systems fail to satisfy the needs of animals.     

灾害与锡林郭勒草地退化,沙漠化

锡林郭勒盟是我国北方重要的畜牧业基地，它以拥有约０．１９７亿ｈｍ２天然草地而著称于世。然而，由于自然灾害和人为不正确的利用而发生了严重退化．到目前，全盟退化草地已占４８．６３％，它不仅为畜牧业生产带来了困难，同时也使一些重要的草地生态因子发生了变化，直接危及了人们的生产和生活。对于退化、沙漠化和草地整治已刻不容缓，应该引起国家有关部门和各级领导的足够重视．     

曲阜地区资源土壤动物调查初报

本文报导了曲阜地区资源土壤动物现状，根据其经济用途，将它们分为食用土壤动物、药用土壤动物、天敌土壤动物和环境指示土壤动物的四大类，并论述了资源土壤动物的开发利用与保护。     

新疆阿勒泰地区实施草原生态保护补奖政策研究

草原生态保护补助奖励政策在阿勒泰地区的实施,标志着该地区草原生态保护进入兼顾民生的发展时期。该地区的政策实施取得了一定的成效,但是还存在补偿标准低、草畜平衡难度大、基本规章制度尚未完善、配套设施及项目资金滞后、农牧民缺乏现代科学技术等问题。造成这些问题的原因有：草地牧草总产量和实际放牧量难以掌控;法律机制不完善;草原产权不清晰;草原生态建设的投融资机制不完善;生态保护观念尚未建立;农业转型困难等。     

近30年青海三江源西部干旱区草地退化特征的遥感分析

使用自20世纪70年代末~2004年的3期遥感图像(70sMSS、90sTM和2004年TM/ETM),研究了近30年青海三江源西部干旱区草地退化的格局与过程,结果表明:整个研究时段内,草地退化发生面积占总草地面积的10%左右,且以草地覆盖度轻度下降为主,其退化面积占总草地退化面积的80%以上,其次是轻度沙化/盐化,相应比重占10%以上。草地退化面积呈东南向西北减少趋势,退化程度呈东南向西北降低格局,而退化类型也由复合型向单一型过渡。整个时段内,草地退化面积呈增加趋势,尤其是沙化面积增加较快。不同海拔、坡度和坡向间草地退化面积差异显著。海拔4 800~5 100m范围内为草地退化发生的主要分布区,4 500~4 800m和5 100m以上草地退化基本相当。退化率较高的坡度级别介于2~8°之间,类似于草地面积随坡度变化的基本趋势。不同坡向呈阴坡、半阴半阳坡高于阳坡的态势。脆弱的基底、极端气候年际间周期波动等限制性因子控制着草地退化的基本格局,人为扰动则决定草地退化的强度和速度。总体看来,研究区地带性自然条件决定的荒漠化草地已占据主导地位,人类活动相对较弱,草地退化程度增加趋势不明显,新的草地退化现象不十分突出。     

中国北方农牧交错带农村土地利用变化因子分析--以内蒙古尧勒甸子村为例

以北方农牧交错带典型生态示范村尧勒甸子村为例,应用参与式农村评估法(PRA)并结合GPS与野外测量,恢复了该村1949年后50 a来的土地利用历史过程与格局,利用GIS分析其1950-1999年的土地利用变化特点.运用因子分析和逐步回归分析方法揭示了人类活动因素对土地利用变化的作用.结果发现1985年以前耕地面积扩大,草地面积减小,沙地面积迅猛持续增加;1985年以后土地利用变化向相反的方向发展,土地利用结构趋向合理.     

土壤动物群落生态学与土壤微生态环境的关系

主要综述了国内外蚯蚓种群、捕食性线虫、蚂蚁、跳虫、螨类等土壤动物与土壤理化性质的关系,以及蚯蚓、白蚁、蜗牛、线虫等土壤动物与土壤酶活性的相关性研究;提出了该学科今后的研究趋势。该学科未来要融合土壤动物和整个农林生态系统的研究为一体,把农林的土壤动物群落生态学及其与土壤微生态环境关系结合起来,耦合土壤动物与植物根系-根际微生态环境,链接农林土壤动物与土壤健康及其害虫生态调控,分析探究它们内在的联系和机制,加强立地调控措施,为森林健康和土壤健康提供科学基础资料。     

不同堆制方法对牛粪和鸡粪发酵脱水的影响

以新鲜鸡、牛粪为材料 ,研究了不同堆制方法对粪便发酵温度与脱水率的影响。结果表明 :牛粪中添加 10 0g·kg-1的稻草在堆制开始 5d ,温度较高 ,但第 3 0天时脱水率反而低于添加 5 0g·kg-1稻草的处理 ;覆盖薄膜降低了粪便脱水速率 ;分批添加物料方法发酵 12d ,堆肥含水量由开始的 5 2 0g·kg-1下降到 5 0 3g·kg-1,而同期 1次添加物料方法发酵 ,堆肥水分含量为 5 5 4g·kg-1。