OUTPUT AND INVESTMENT FRONTIERS OF UNITED STATES IRRIGATED AGRICULTURE1

ABSTRACT: Economic models sometimes indicate that irrigation water is misallocated in agriculture, especially when it appears that the marginal value product is higher in other uses (such as for hydro-power). Historically, trends tend to contradict this reasoning, however, especially since irrigation has grown from 20 million acres in 1940 to over 50 million acres in 1980. Results of this study tend to indicate that as agriculture becomes more and more intensive (in terms of inputs), irrigation is part of that long term trend. Further, major economic variables, such as output and investments in agriculture, appear to be more highly correlated with irrigated land than with dryland agriculture. Recent data indicate an upper limit of about 320 million acres for dryland farming in the United States, while no such constraint is apparent for irrigated agriculture.     

A forage-based vision of Ontario agriculture

The necessity of incorporating societal and environmental concerns into publicly funded agricultural initiatives in research, extension, and practice is increasingly evident. Agriculturalists are urged to acknowledge and respond to societal concerns before an insensitive and largely ill-informed urban majority assumes a dominant posture in agricultural policy. In recent history, the availability of unrealistically cheap energy encouraged the evolution of a form of commercial agriculture unfettered by sound ecological principles. At present, external, resource-intensive intervention of increasing magnitude is needed to compensate for the apparent ecological instability generated by practices such as intensive cereal management or conservation tillage practices. Polarization of the enterprises of plant and animal agriculture to enable centralized, concentrate-intensive, confinement feeding has disrupted the natural cycling of nutrients and carbon in the soil, encouraged the withdrawal of perennial forages from crop rotations, and invoked a widely ramifying network of agricultural and societal problems. Solutions to these problems must evolve from a holistic and far-reaching appraisal of causes, rather than from a piecemeal approach to individual symptoms.     

红外法测定不同行业废水中石油类/动植物油

用红外光度法和非分散红外光度法对几种有代表性水样的石油类/动植物油进行了测定,对GB/T16488-1996标准中一些步骤的可操作性及必要性进行了分析,并提出相应建议。     

BIOMONITORING OF AIR POLLUTION IN A SEASONALLY DRY TROPICAL SUBURBAN AREA USING WHEAT TRANSPLANTS

Air pollution has been identified as a serious problem throughout the world which causes tremendous loss to the crops by affecting plant growth and yield. Earlier, air pollution was restricted to urban and industrial regions. Over the last few decades, however, it has become evident that pollutants can be transported over long distances and hence their impact may be felt widely over rural areas. The present study was conducted to evaluate the impact of urban air pollution on suburban agriculture with respect to the changes in photosynthetic rate, stomatal conductance, water-use efficiency, plant height, numbers of tillers, leaves, ears and seeds, chlorophyll, carotenoid, protein, phenol, ascorbic acid, nitrogen and sulphate-sulphur contents and seed weight of pot-grown wheat plants (Triticum aestivum var. HUW 468) kept at different sites around Varanasi city receiving varying levels of pollution load. Mean concentrations of were monitored. The study clearly showed that plants are negatively affected by the ambient levels of air pollutants. Reduction in various parameters directly corresponded with the air pollution levels at different sites.     

The Environmental Implications of Soil Erosion in the United States

Soil erosion has both on-farm and off-farm impacts. Reductionof soil depth can impair the lands productivity, and thetransport of sediments can degrade streams, lakes, and estuaries. Since 1933, soil conservation policies have existedin the United States. Originally they focused on the on-farmbenefits of keeping soil on the land and increasing net farmincome. Beginning in the 1980s, however, policy goalsincreasingly included reductions in off-site impacts of erosion.As a consequence of conservation efforts associated withexplicit U.S. government policies, total soil erosion between1982 and 1992 was reduced by 32% and the sheet and rillerosion rate fell from an average of 4.1 tons per acre per yearin 1982 to 3.1 tons per acre in 1992 while the wind erosion ratefell from an average of 3.3 tons per acre per year to 2.4 tonsper acre per year over the same period. Still, soil erosion isimposing substantial social costs. These costs are estimated tobe about $37.6 billion annually. To further reduce soil erosionand thereby mitigate its social costs, there are a number ofpolicy options available to induce farmers to adopt conservationpractices including education and technical assistance, financial assistance, research and development, land retirement, andregulation and taxes.     

Integration of Case Studies on Global Change by Means of Qualitative Differential Equations

We present a novel methodology to integrate qualitative knowledge from different case studies on Global Change related issues into a single framework. The method is based on the concept of qualitative differential equations (QDEs) which represents a mathematically well-defined approach to investigate classes of ordinary differential equations (ODEs) used in conventional modeling exercises. These classes are defined by common qualitative features, e.g., monotonicity, signs, etc. Using the QSIM-algorithm it is possible to derive the set of possible solutions of all ODEs in the class. By this one can formulate a common, qualitatively specified cause–effect scheme valid for all case studies. The scheme is validated by testing it against the actually observed histories in the study regions with respect to their reconstruction by the corresponding QDE. The method is outlined theoretically and exemplary applied to the problem of land-use changes due to smallholder agriculture in developing countries. It is shown that the seven case-studies used can be described by a single cause–effect scheme which thus constitutes a pattern of Global Change. As a generally valid prerequisite for sustainability of this kind of land-use the presence of wage labor is shown to represent a decisive factor. This revised version was published online in July 2006 with corrections to the Cover Date.     

Combating Desertification: Building on Traditional Knowledge Systems of the Thar Desert Communities

The Thar Desert of western India is known for its rich and ancient culture system and traditions. The communities have long been part of the Thar Desert ecosystem and have evolved specific strategies to live in harmony with its hostile environment. This culture has provided several miracle plants of immense food and medicinal value to modern civilisation. The ancient rural livelihood knowledge system reflects time-tested techno-scientific knowledge with a proven track record of sustainability, especially during natural hazards like drought and famines. In addition, several of the traditional skills of local communities in arts and crafts, music and instruments have made modern man aware of the art and techniques of sustainably utilising local biological resources and preserving their biodiversity along with using waste products of the forests, without harming the desert ecosystem. Traditional cultural and socio-religious values are fast dwindling under the impact of materialistic approach, industrialisation and development. This paper endeavours to illustrate the need to assist and propagate indigenous rural livelihood systems rather than mindlessly replace or abandon them as a result of state bureaucracies.     

The water quality of the Vrgorska Matica River

The article presents the results of investigations carried out on the 42 km long Vrgorska Matica River, which flows through the 15 km long Vrgorsko polje (polje = field) which covers an areaof 3000 ha, and is at 24 m a.s.l., located in Southern Croatia.It covers the years 1997–2000 after this field had been reclaimed for agricultural use.The purpose of the investigations was to evaluate the influence of the Vrgorska Matica River which is part of the catchment areaof the Trebizat River, on the water quality in Modro Oko Lakeand Prud Spring, which are used for water supply and are locateddownstream of the Vrgorska Matica River on the right bank of theNeretva River.The water quality was evaluated by using the quality index basedon the following nine parameters: temperature, mineralization, corrosion coefficient, K = (Cl + SO₄)/HCO₃, dissolvedoxygen, BOD₅, total N, protein N, total phosphorus and totalcoliform bacteria (100 mL)^-1 (MPN coli (100 mL)^-1) for which concentrations C ₉₅ are calculated. After completingthe nine parameters the results of C ₉₅ were recorded andtransferred to the score table to obtain the q-value. The q-value used is an attempt to quantify environmental factors which would otherwise be qualitative. For each parameter the q-value was multiplied by a weighting factor based upon the relative significance of the parameter. The nine resulting scores values were then added to arrive at an overall water quality index (S₉₅).According to this index the water can be classified into four categories. The first category, according to the Croatian Water Classification Act (Official Bulletin No. 77,1998), includes ground and surface waters used for drinking or in the food industry either in its natural state or after disinfection, and surface water used for raising high-quality species of fish, ranging from 85–100 scores; the second category includes waterused in its natural state for swimming and recreation, sports orfor other species of fish and the treated water used for drinkingand other industrial purposes ranging between 70–85 scores. Thethird category includes water used in industry with no specific requests upon water quality and in agriculture ranging from 50–70 scores; the fourth category includes water used only afterbeing treated in areas with water shortage which is less than 50 scores.According to results obtained by investigations, the water of theVrgorska Matica River and Prud Spring falls into the second (II)category, while water from the Modro Oko Lake belongs to the first (I) category. This means that the Matica River water does not influence the water quality of the Modro Oko Lake. This lakewater quality is influenced by the Rastoka Matica River from theRastoko polje which is located upstream from the Vrgorska MaticaRiver. This has been proved by dyeing tests.     

Use and abuse revisited: Response to Pluhar and Varner

In her recent Counter-Reply to my views, Evelyn Pluhar defends her use of literature on nutrition and restates her argument for moral vegetarianism. In his Vegan Ideal article, Gary Varner claims that the nutrition literature does not show sufficient differences among women, men, and children to warrant concern about discrimination. In this response I show how Professor Pluhar continues to draw fallacious inferences: she begs the question on equality, avoids the main issue in my ethical arguments, argues from irrelevancies, misquotes her sources, equivocates on context, confuses safety with morality, appeals to fear, confuses correlation with cause, fails to evaluate scientific studies, draws hasty conclusions from insufficient data, ignores a large amount of data which would call her views into question, does not follow good scientific or moral argumentation, objectionably exceeds the limits of her expertise, and resorts to scapegoating. I also argue that Professor Varner fails to make his case because he offers virtually no evidence from scientific studies on nutrition, relies on outdated and fallacious sources, makes unsupported claims, ignores evidence that would contravene his claims, draws hasty conclusions based on weakly supported hypotheses rather than facts, employs a double standard, appeals to ignorance, does not evaluate arguments from his sources, and makes anad hominem attack on a respected nutritionist when his focus should be on evaluating the evidence and arguments from the scientific studies themselves. Neither Varner nor Pluhar have responded sufficiently to the real issue in my arguments, that of discrimination and bias in the vegan ideal.     

In defense of the vegan ideal: Rhetoric and bias in the nutrition literature

Much of the scientific literature on vegetarian nutrition leaves one with the impression that vegan diets are significantly more risky than omnivorous ones, especially for individuals with high metabolic demands (such as pregnant or lactating women and children). But nutrition researchers have tended to skew their study populations toward new vegetarians, members of religious sects with especially restrictive diets and tendencies to eschew fortified foods and medical care, and these are arguably the last people we would expect to thrive on vegan diets. Researchers also have some tendency to play up weakly confirmed risks of vegan dietsvis-à-vis equally weakly confirmed benefits. And, in spite of these methodological and rhetorical biases, for every nutrient which vegans are warned to be cognizant of, there is reason to believe that they are not at significantly greater risk of nutritional deficiency than omnivores.