Alternative Agricultural Practices Research Articles

An alternative agriculture system is defined by a distinct expression profile of select gene transcripts and proteins.

Conventional agriculture has relied heavily on chemical inputs that have negatively impacted the environment and increased production costs. Transition to agricultural sustainability is a major challenge and requires that alternative agricultural practices are scientifically analyzed to provide a sufficiently informative knowledge base in favor of alternative farming practices. We show a molecular basis for delayed leaf senescence and tolerance to diseases in tomato plants cultivated in a legume (hairy vetch) mulch-based alternative agricultural system. In the hairy vetch-cultivated plants, expression of specific and select classes of genes is up-regulated compared to those grown on black polyethylene mulch. These include N-responsive genes such as NiR, GS1, rbcL, rbcS, and G6PD; chaperone genes such as hsp70 and BiP; defense genes such as chitinase and osmotin; a cytokinin-responsive gene CKR; and gibberellic acid 20 oxidase. We present a model of how their protein products likely complement one another in a field scenario to effect efficient utilization and mobilization of C and N, promote defense against disease, and enhance longevity.

Irrigated crop production is associated with less malaria than traditional agricultural practices in Tanzania

There is concern that crop irrigation that results in increased numbers of vector mosquitoes will lead to a rise in malaria in local communities. We evaluated the level of malaria experienced in 3 communities in northern Tanzania with different agricultural practices: rice irrigation, sugar-cane irrigation and traditional maize cultivation. Five cross-sectional surveys were used to measure the prevalence of infection with falciparum malaria in 1–4 years old children in each community over a period of 12 months. Active case detection was also carried out to record clinical episodes of malaria during the study period. Information on antimalarial measures was also recorded. Results from the cross-sectional surveys showed that the overall prevalence of malaria parasites was less near the rice irrigation (12.5%) and sugar-cane (16.9%) schemes than the savannah village (29.4%). There were also significantly fewer clinical episodes of malaria in the rice village (15 cases/1000 child-weeks at risk [cwars]) than either the sugar-cane (36 cases/1000 cwar) or savannah (40 cases/1000 cwar) villages. Overall, rice irrigation was associated with less malaria than alternative agricultural practices, despite the considerable numbers of vectors produced in the paddies. This finding supports other studies that indicate that irrigation in much of sub-Saharan Africa will not lead to increased malaria. Nonetheless, African governments planning irrigation projects need effective policies to encourage local communities to use personal protection measures, such as insecticide-treated bednets, and to ensure that these communities have access to effective antimalarial drugs and efficient health services.

Biodiversity of Collembola in tropical agricultural environments of Espı́rito Santo, Brazil

Despite the environmental importance of Collembola, basic information on the occurrence and ecology of these soil microarthropods is lacking, especially in Neotropical and agricultural environments. To address such gaps in information this research was conducted with objectives to determine what Collembola species inhabit agricultural soils of Espı́rito Santo, Brazil; obtain a record of the seasonal abundance of Collembola in this area; and to investigate effects of alternative agricultural practices on Collembola in this tropical environment. Research field sites are located in Domingos Martins municipality, Espı́rito Santo (20°23′S, 41°03′W) and consist of three sites: (A) fertilizer site, with two fertilizer treatments, organic fertilizer and inorganic fertilizer; (B) tillage site, with two tillage treatments, no tillage and conventional tillage; and (C) mulch site, with two mulch treatments, mulch and no mulch. Experimental plots have received similar treatments since the sites were established (1991, 1992) and a variety of crops are grown on the sites annually. From December 1999 to November 2000, soil core samples (4.8 cm diameter) were taken randomly from the surface 10 cm of each plot every 28–71 days. Tullgren funnels were used to extract Collembola from the soil samples and the Collembola collected were identified and quantified. A total of 9650 collembolan specimens was collected from 88 samples taken at approximately 2 month intervals, averaging 60,600 Collembola per meter square, including 38 species and three probable new species. Averaged across sites and treatments, total collembolan density was greater in September than in December. Total collembolan densities were greater with no tillage versus conventional tillage and with mulch versus no mulch.

Transport and fate of atrazine and lambda-cyhalothrin in an agricultural drainage ditch in the Mississippi Delta, USA

Drainage ditches are integral components of agricultural production landscape, yet their contaminant mitigation capacity has been scarcely examined. If ditches are indeed capable of contaminant mitigation, then their use may serve as an alternative agricultural best management practice (BMP). A 50 m portion of an agricultural drainage ditch, located in the Mississippi Delta Management Systems Evaluation Area (MDMSEA), USA, was amended with a mixture of water, atrazine (2-chloro-4-ethylamino-6-isopropylamino- s-triazine) (herbicide) and lambda-cyhalothrin (λ-cyano-3-phenoxybenzyl-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethyl cyclopropanecarboxylate) (insecticide), simulating a storm runoff event. Pesticide amendment was achieved using a diffuser to disperse the mixture at an inflow point along the ditch (designated as “0 m”). Pesticide concentrations in water, sediment, and plants were monitored for 28 days. One hour following initiation of simulated runoff, mean percentages of atrazine concentrations measured in water and sediment were 37 and 2%, respectively, while mean percentages of lambda-cyhalothrin concentrations in water and sediment were 12 and 1%, respectively. Atrazine and lambda-cyhalothrin mean percentage concentrations in plants ( Polygonum (water smartweed), Leersia (cutgrass), and Sporobolus (smutgrass)) were 61 and 87%, respectively. Therefore, plants serve as an important site for pesticide sorption during runoff events. Aqueous concentrations of both pesticides decreased to levels which would not elicit non-target toxicological effects by the end of the 50 m portion of the drainage ditch. This research provides fundamental answers concerning the capability of vegetated agricultural drainage ditches to mitigate pesticide-associated storm water runoff.

A Sustainable Agro-ecological Solution to Water Shortage in the North China Plain (Huabei Plain)

A highly seasonal rainfall pattern in the agriculturally productive region of Huabei Plain has been widely considered in China as a handicap to maximizing agricultural production. Enhancing this perception is the traditional policy of achieving provincial or regional self-sufficiency in grain production, which underlies China's production quotas. The Chinese government has decided to overcome this perceived handicap in order to meet the increasing water demands of urban populations and to achieving its grain quotas by constructing aqueducts to transport about 14 2 10 9 m 3 of water from the Dan Jiang Reservoir into the Huabei Plain. However, this engineering construction solution threatens the long-term market competitiveness of the region by driving up the cost of water relative to the value of the product, by taking too long to complete and by being unproven in its effectiveness. This solution also threatens the existing ecosystem by interfering with the natural hydrology, and it risks exacerbating the ongoing groundwater overdrafts that are contributing to the formation of numerous sinkholes and ground surface cracks in the region, as well as to the intrusion of sea water. A more certain, ecologically sound solution can be found in alternative agricultural practices and cropping systems. Reducing the winter wheat production by a relatively small acreage, combined with the increased use of water-saving irrigation systems, can more than replace the effectively usable 10 2 10 9 m 3 of water that the engineering construction project would transport via aqueducts. The recommended alternative cropping system would solve the water shortage problem immediately. This alternative would enable the government to allocate funds where they are more needed, such as to the clean-up of extensively polluted rivers and to ecological restoration, which bears on the sustainability of agriculture and food supply in China.

The Risks and Benefits of Genetically Modified Crops: A Multidisciplinary Perspective

Peterson, G. D., S. Cunningham, L. Deutsch, J. Erickson, A. Quinlan, E. Ráez-Luna, R. Tinch, M. Troell, P. Woodbury and S. Zens 2000. The Risks and Benefits of Genetically Modified Crops: A Multidisciplinary Perspective. Conservation Ecology 4(1):13. https://doi.org/10.5751/ES-00195-040113

ANALYSIS OF NITROGEN MANAGEMENT STRATEGIES USING EPIC1

ABSTRACT: This paper illustrates a method of using a hydrologic/water quality model to analyze alternative management practices and recommend best management practices (BMPs) to reduce nitrate‐nitrogen (NO3‐‐N) leaching losses. The study area for this research is Tipton, an agriculturally intensive area in southwest Oklahoma. We used Erosion Productivity Impact Calculator (EPIC), a field‐scale hydrologic/water quality model, to analyze alternative agricultural management practices. The model was first validated using observed data from a cotton demonstration experiment conducted in the Tipton area. Following that, EPIC was used to simulate fertilizer response curves for cotton and wheat crops under irrigated and dryland conditions. From the fertilizer response functions (N‐uptake and N‐leaching), we established an optimum fertilizer application rate for each crop. Individual crop performances were then simulated at optimum fertilizer application rates and crop rotations for the Tipton area, which were selected based on three criteria: (a) minimum amount of NO3‐‐N leached, (b) minimum concentration of NO3‐‐N leached, and (c) maximum utilization of NO3‐‐M. Further we illustrate that by considering residual N from alfalfa as a credit to the following crop and crediting NO3‐‐N present in the irrigation water, it is possible to reduce further NO3‐‐N loss without affecting crop yield.

Impact of agricultural management on nitrate concentrations in drainage waters

AbstractNitrate contamination of surface water resulting from inputs of agricultural drainage water is a widespread problem. To learn whether alternative agricultural practices might ameliorate this problem, we measured NO-3 in water draining from three neighboring fields from 1970 to 1992. Drainage water from two fields fertilized with N exclusively as composted and liquid manure had NO-3 concentrations less than 2 ppm (20% of the Public Health Service recommended limit for drinking water). When these fields were converted to a corn/soybean rotation fertilized with anhydrous ammonia, NO-3 concentration increased about 7- to 10-fold. On a third field, corn was always fertilized with anhydrous ammonia. Changing this field from a rotation of corn, oats and hay to corn/soybean and increasing the rate of N fertilization by about 18% almost doubled the NO-3 concentration in the drainage water. The corn/soybean rotation most prevalent in the Corn Belt today resulted in high NO-3 concentrations in the drainage water, while the alternative system prevented NO-3 problems.

Nitrate leaching from soils under a maize-wheat-maize sequence, two irrigation schedules and three types of fertilisers

To implement measures to tackle the nitrate leaching problem it is necessary to assess the effect of alternative agricultural practices in vulnerable zones. A 3-year experiment was conducted at La Poveda Field Station (30 km southeast of Madrid, Spain) to assess the effects of irrigation schedules (conventional vs. efficient) and fertiliser types (unfertilised control, urea, Floranid32 (a slow-release N fertiliser), and municipal organic waste (MOW) compost) on nitrate leaching, grain yield and N uptake by plants. Treatments were combined in a factorial model and distributed to 24 plots. Chemical fertilisers were applied at the rate of 150 kg N ha −1 to maize (1993 and 1995 growing seasons) and 100 kg N ha −1 to wheat (1994 growing seasons). The MOW compost was applied at a single dose before 1993 maize planting at the rate of 27.5 Mg ha −1. Conventional irrigated plots were overwatered and the water input in efficient irrigated plots was dosed according to plant consumption. Nitrate discharge was calculated by multiplying the seasonal drainage volume by the concentration of nitrates in soil water solution, both at 1.4 m soil depth. Seasonal drainage was calculated by using the water balance equation after measuring water movement (tensiometers) and water storage throughout the soil profile (neutron probe). Nitrate concentration was measured in samples extracted with ceramic cups. Drainage losses throughout the experiment were 184 and 38 mm in plots irrigated with conventional and efficient schedules, respectively. Corresponding nitrate-nitrogen discharge in both sets of plots were 128 and 25 kg N ha −1 across fertiliser types. The nitrate discharge in unfertilised plots from the soil N reserve was on average half than that in fertilised ones. The MOW compost treatment combined with efficient irrigation showed promise in controlling nitrate discharge. Maize yields were unaffected by fertiliser type, but wheat yields decreased by 33% in unfertilised plots. It is concluded that, at a given rate of chemical fertiliser, nitrate loading to the aquifer can be traced to drainage discharge and that safe loading of MOW compost to soils requires control of water inputs.

A watershed-based system for the integrated management of surface water quality: the GIBSI system

This paper presents a general description and the state of progress of the GIBSI system, a watershed-based software system for integrated management of surface water quality. This spatial support-decision system is designed to assist decision makers as well as water resources professionals. An integrated structure composed of mathematical models, a Geographical Information System (GIS) and a DataBase Management System (DBMS) characterizes the system. This means interactions between users and system components are made through a single user-friendly interface. A simple scenario approach is used to examine the impact of alternative urban, industrial, and agricultural management practices on surface water quality. Interpretation of results is based on comparing different management scenarios with a reference state or other previously defined scenarios.

The killing fields: Science and politics at Berkeley, California, USA

Over the past several decades, a group of scholars at the Berkeley campus of the University of California have frequently challenged many of the dominant themes of contemporary agricultural research. In their work, they have organized curricula questioning the assumptions of conventional agriculture and its sciences while encouraging the development of alternative agricultural practices based on principles of ecology. Their collective critique has stimulated an intellectual climate calling forth a scrutiny of the university's role in the production of knowledge and the social consequences of its works. The result of this intellectual project has been a group that has also largely challenged the dominant themes of the modern university. In place of a setting where ideas are a passive currency, the modern university is a place where knowledge and power are manifest in a dialectic that is revealed not simply by the production of knowledge, but its destruction as well. It is in this context that the recent history of a group of scholars at the University of California provides a striking testimony concerning the disturbing character of science in the modern university. The ecological and social dimensions of “killing fields” that captures the contemporary hazards of food and fiber production in California is also reflected in the gradual demise of a group of researchers at Berkeley who have endeavored to provide an alternative vision of agriculture.

Simulating N leaching in furrow irrigated corn

Crop simulation models are increasingly used to evaluate the effect of alternative agricultural practices on crop yields and the environment. Difficulty in obtaining concise field data often requires that simulation results reflect a single point assumed to represent average field condition. Results of this study indicate that the single point analysis can have significant effects upon estimates of nitrogen leaching and crop yield under various surface irrigation practices. Practices considered illustrate the effects of differences in infiltration along the row, between irrigations, and between irrigated sets. Attempts to add intermediate realism in describing the irrigation system may not improve yield and leaching estimates over the single point simulation when compared to simulation results where even more realism is introduced.

Avian Communities of Fragmented South‐Temperate Rainforests in Chile

The diversity and relative abundance of south‐temperate rainforest birds decreased as the size of the habitat patch decreased. Ecological categories, including endemics, mutualists (pollinators, seed dispersers), understory species, and species dependent on large trees, were not differentially sensitive to patch size. Nevertheless, most of the species with at least marginally significant declines were endemic (6 of 7 species), covered nesters (6 of 7 species), and understory dwellers (5 of 7 species). Some mutualists and big‐tree users were also affected. The losses will become more severe as clearing of the forest continues. Possible mitigation measures include leaving small stands of forest and corridors between habitat patches and, in certain circumstances, alternative agricultural practices.

Sustainable Agriculture: A Twenty-First-Century System

U.S. agriculture has been very productive during the past fifty years. A number of unexpected consequences, however, are believed to be detrimental to the long-term interests of our nation's agriculture and natural resources. In response to this issue, the Food, Agriculture, Conservation and Trade Act of 1990 mandates that the U.S. Department of Agriculture conduct research and education programs on alternative agricultural systems. These must be productive, economically viable, and environmentally sound; they must conserve natural resources, make optional use of on-farm resources, and enhance the quality of life for farmers and ranchers, members of rural communities, and society as a whole. The Sustainable Agriculture Research and Education (SARE) Program has evolved as an important initiative for development and promotion of alternative agricultural practices and production systems. This article describes sustainable agriculture and its role in the development of a philosophy for identification of research, education, and policy initiatives for twenty-first-century U.S. agriculture.

Meeting Report: Agricultural Chemical Utilization and Human Health

The public is justifiably concerned about the human health effects of agricultural chemicals. The many gaps in information about the mechanisms of toxic action, human exposures, and the nature and extent of human health effects are large. Very few older pesticides, in particular, have been tested for human health effects. Workers who produce, harvest, store, transport, process, and prepare food and fibers are exposed to many chemicals that are potentially hazardous and that are used in agriculture. The occupational health of these workers has not been adequately studied, and protective efforts have sometimes been minimal. Valid and accurate risk assessment is best based on sound information about how chemicals, in this case agricultural chemicals, are involved in toxic events-their mechanisms of action. These health effects include tumor promotion, chronic and acute neurotoxicity, immunotoxicity, and reproductive and developmental toxicity. Another key part of risk assessment is exposure assessment. Fundamental studies of the toxicology of target organisms and nontarget organisms exposed to agricultural chemicals are needed to discover and develop better solutions to the problems of agricultural pest control, including better formulations, optimal application rates and public education in safety and alternative agricultural practices. The large number of pesticides that have never been adequately tested for effects on human health is particularly worrisome in light of emerging information about delayed nervous system effects.

Agricultural chemical utilization and human health.

The public is justifiably concerned about the human health effects of agricultural chemicals. The many gaps in information about the mechanisms of toxic action, human exposures, and the nature and extent of human health effects are large. Very few older pesticides, in particular, have been tested for human health effects. Workers who produce, harvest, store, transport, process, and prepare food and fibers are exposed to many chemicals that are potentially hazardous and that are used in agriculture. The occupational health of these workers has not been adequately studied, and protective efforts have sometimes been minimal. Valid and accurate risk assessment is best based on sound information about how chemicals, in this case agricultural chemicals, are involved in toxic events--their mechanisms of action. These health effects include tumor promotion, chronic and acute neurotoxicity, immunotoxicity, and reproductive and developmental toxicity. Another key part of risk assessment is exposure assessment. Fundamental studies of the toxicology of target organisms and nontarget organisms exposed to agricultural chemicals are needed to discover and develop better solutions to the problems of agricultural pest control, including better formulations, optimal application rates and public education in safety and alternative agricultural practices. The large number of pesticides that have never been adequately tested for effects on human health is particularly worrisome in light of emerging information about delayed nervous system effects.

Economic feasibility of agricultural management practices for reducing sedimentation in a water supply lake

The economic feasibility of using alternative agricultural management practices to reduce sedimentation and enhance water storage capacity is evaluated for a water supply lake located in northern Missouri (USA). Sedimentation of lakes is a major concern in this region because many of them serve as a municipal water supply. Net sediment delivery to the lake is estimated for 18 agricultural management practices and eight storm events using the Agricultural Nonpoint Source Pollution (AGNPS) model. Event-based sediment delivery is aggregated to an annual basis using daily rainfall and a sediment yield curve estimated with the AGNPS model. Sediment reduction benefits are estimated by the savings in groundwater pumping costs. Many of the management practices that reduce sediment delivery to the lake are not likely to be adopted by farmers because they reduce net returns to land and management relative to practices employed in 1987 and 1988. Decreases in net returns are largest when clover replaces maize in the rotation. Net returns are somewhat lower with no tillage than with minimum tillage and highest with a maize/soybean rotation, maize/soybean/wheat rotation or continuous soybeans. Sediment reduction benefits are relatively small and insufficient to offset the decreases in net returns to farmers. Five practices increase net returns and have positive social value, namely those involving the maize/wheat, maize/soybean/wheat or continuous soybean rotation and practices that maximize total net returns in the watershed.

Sweeping Changes Proposed in Federal Agricultural Research

Three members of the Senate Agriculture, Nutrition & Forestry Committee, including its chairman and ranking minority member, have recently introduced three bills aimed at making it easier for farmers to adopt sustainable or alternative agricultural practices. Two of the bills would make sweeping changes in the federally supported agricultural research program. The committee is currently working on a new 1990 farm bill that Congress is expected to enact by the end of the year. Provisions of the three bills are likely to be folded into this omnibus legislation. The sustainable, as defined by the committee's ranking minority member, Sen. Richard G. Lugar (R.-Ind.), means an agricultural system that is economically viable and environmentally sound over the short and long term (C&EN, March 5, page 26). Bills introduced by committee chairman Sen. Patrick J. Leahy (D.-Vt.), Sen. Thomas A. Daschle (D.-S.D.), and Lugar all contain provisions that would advance research in sustainable ...

Ground water research, information, and policy needs: Strategies and priorities for extension

AbstractThe Cooperative Extension Services in many states have concentrated on educational publications and programs which describe the complexities of the hydrologic cycle and where pollutants can enter the system. Recognizing that farming is a prime source of nonpoint source pollution in some areas, extension programs have focused on alternative agricultural practices which can reduce that pollution. Both national and state extension services have published recommendations on increasing public awareness, developed linkages with research, and provided leadership in education about pollution problems and how to solve them. The current national task forces on extension priorities include “water quality” as one of eight key areas for future extension emphasis. Alternative farming practices which can help reduce the pollution levels from agriculture include careful soil sampling, interpretation of analyses, setting yield goals, and matching nutrient applications to crop needs. Modified methods of nutrient application can also help. Reduced tillage, crop rotations, increased use of legumes, and keeping cover on the land through a greater part of the year can all help. Reduced applications of pesticides and use of alternative pest control measures have potential to improve ground water quality. There are economic as well as environmental reasons to reduce chemical and fertilizer applications in agriculture. This is a critical time for producers and researchers to examine alternative practices which can help improve ground water quality for future generations.

Watershed Loading Functions for Nonpoint Sources

A modeling procedure has been developed to estimate nonpoint source pollution from agricultural runoff in large watersheds. The procedure is based on simple equations for runoff and soil loss prediction. It is designed for use in situations where resources are not available for extensive water quality sampling or more sophisticated modeling efforts. The simple models or loading functions were tested by comparing predicted and observed nitrogen and phosphorus mass fluxes in streamflow from a 391-km² Pennsylvania watershed for a 16-month period. The comparisons indicated that loading functions provided reasonable estimates of dissolved nitrogen, solid-phase nitrogen and total phosphorus mass fluxes in runoff from the watershed. Rather, these simple methods are most suitable as screening devices to: (1)Identify the approximate magnitudes of nonpoint source loading of pollutants in agricultural runoff; and (2)evaluate the likely changes in loadings associated with alternative agricultural management practices.