Overview

Implementation / Demonstration of Best Management Practices on Model Farms in Louisiana


Issue

Conventional tillage practices result in significant losses of agricultural inputs (i.e. nitrogen and phosphorus fertilizers, pesticides, etc.) into the Mississippi River watershed. Agricultural inputs, urban effluent, and industrial point-sources of nutrient pollution can ultimately end up in the Gulf of Mexico and contribute to the 5,460 square mile dead zone.


Goals

  • Demonstrate best management practices which improve soil health and water quality while also promoting agricultural system sustainability to reduce agricultural inputs contributing to the dead zone located in the Gulf of Mexico.
  • Identify a portfolio of practices that are economically profitable and environmentally sustainable.

Model Farms Best Management Practices

Maintaining surface cover limits the exposure of soil to losses due to wind and water erosion. This, in turn, reduces the amount of potential runoff from fields, as well as, losses of soil, nutrients, and chemicals in runoff. This can be accomplished by (a) implementing reduced or conservation tillage, (b) residue management, (c) planting cover crops, (d) proper crop selection and management, and (e) water management. All of these practices collectively result in soil surface protection from residue and cover crops, preserved strong soil aggregates, improved water storage and movement through the soil profile.

The implementation of these practices will result in improved soil health which subsequently reduces reliance on synthetic fertilizers, pesticides and herbicides. Due to improved organic matter content, microbial activity, aggregate stability, nutrient cycling, moisture condition, and increase population of beneficial organisms in the soil, the productivity potential is not entirely dependent on added agricultural inputs. Lesser inputs without compromising crop productivity will reduce losses of agricultural inputs through runoff and erosion. Residue from main crops and cover crops are sources of nutrients and food for microorganisms while practicing minimum tillage prevents destruction of soil aggregates and fungal communities. These increase nutrients supplying and water holding capacity of the soil. Most importantly, soils can contain these nutrients and other agricultural inputs into its system rather than wash out during excessive rainfall.

Utilizing best management practices will minimize inputs while maximizing their efficiency within the field reducing potential losses through erosion. Practices including fertility management allows the soil to maintain optimum conditions for nutrient uptake and vegetative growth. This is done by utilizing soil testing and variable rate applications to apply nutrients where and when they are needed, reducing losses due to excess fertilizer applications. Cover crops act as nutrient scavengers, taking up mobile nutrients before they can be lost through leaching and runoff. Additionally, legumes fix atmospheric nitrogen, potentially reducing fertilizer input needs. Chemical inputs can also be reduced through integrated pest management, by targeting specific needs and maximizing the effectiveness. By including cover crops and crop rotation, not only is the life cycle of pests interrupted, reducing the need for chemical inputs, but the diversity of biomass supports diverse communities of beneficial microorganisms, providing barriers to plant diseases. Further protection of the vegetative community is provided through the use of seed protectants which reduce potential losses by localizing the placement of pesticide to the area of contact.


Approach and Verifiable Outcomes

The best management practices will be implemented at Sugarcane Model Farm in Napoleonville and Cotton & Grain Crops Model Farm in Somerset. A production field under producer’s standard practices (Producer Farm) will be established adjacent to each of these model farms. Both the Model and Producer Farms at each location will be installed with flume and automated water sampler for water quality monitoring and total nutrient load estimation. Plant data including main crop yield and cover crops biomass will be collected. Full analysis of elemental composition of these collected plant parts will be performed to estimate nutrient (i.e., nutrient and phosphorus) use efficiency and nutrients recovered from the soil. Soil samples will be collected at critical growth stages during the growth of main crop and cover crops to monitor nutrient cycling, biological activity, soil physical properties, and organic matter accumulation. These metrics will be used to evaluate the performance of the proposed Model Farm and Producer Farm in terms on agronomic, economic, and environmental sustainability.

A portfolio of practices that are economically profitable and environmentally sustainable will be identified. The marginal impact of any conservation practice is an important component of conservation benefits measurement. Focusing solely on a system of practices deters some from adopting the whole suite of conservation methods due to challenges from an implementation standpoint and a financial standpoint. Identifying practices that maximize nutrient loss reduction benefits, either through one practice and/or combining with one or more practice is an unmet need of the farmer in Louisiana. Through the Model Farms project, we will be able to identify the value of conservation practices individually and in combination with other conservation practices. Relying on the results generated through the project and the literature, we will be able to value the ecosystem services that are generated, consequently mitigation of the Hypoxia Zone in the Gulf. A conservation practices budget will be generated that will include the practice, its marginal impact on nutrient reduction and/or nutrient losses to bodies of water, and overall profitability. The attached schematic presents the outline of the estimation method.


Outreach Program

The Sugarcane and Cotton & Grain Crops Model Farms will be sites for outreach and educational programs for students, producers, consultants, and extension personnel from state and government agencies from Louisiana, the southern region, and states within the Mississippi River watershed. Field day demonstrations and workshops will be conducted, to provide (1) hands-on experience for implementing these different best management practices, and (2) information on the production and economic benefits, and most importantly, (3) to demonstrate the positive long-term impacts of the BMPs on the environment. Information obtained from the Model Farms will be disseminated regarding the potential effects of employing similar best management practices on agricultural runoff at a state, regional, and national level. Specifically, we will target the agricultural lands of all the states and Canadian provinces known to contribute non-point sources of pollution to the Mississippi River watershed.



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The LSU AgCenter and the LSU College of Agriculture

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