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SUSTAINABILITY


control, leading to increased input needs and potentially crop failures. Additionally, monoculture can cause greater weed species diversity within a field.7 Meadowfoam is an important rotational element of our growers’ cropping system, as it easily adapts to no-till and the FPC modelling shows it can decrease the fieldprint of our farmers when used in rotation with one of their primary crops. Table 1 outlines the three cropping systems that were modelled using the FPC. These are typical crop rotations available to farmers in the south Willamette Valley production area. System 1 represents alternate year production of ARG and meadowfoam. This system allows the grower to rotate between a broadleaf and grass species allowing for continuous long term NT with minimal soil disturbance and the potential to maximise the integrated pest management (IPM) advantages of crop rotation.


System 2 represents a continuous ARG cropping system. In the absence of suitable crop rotation options this can become a dominant feature of south Valley ARG production. The disadvantage of this system is the lack of crop rotation and the eventual need to conventionally till the soil to manage crop residue and break pest cycles.


System 3 is a modified version of System 1 that still allows for the use of continuous NT but using a slightly longer cycle between meadowfoam crops.


Metrics


While the FPC offers at least seven metrics for sustainability, three initial metrics were chosen as a beginning point to make comparisons of the cropping systems: energy consumption, soil conservation, and water quality.


Energy consumption


The final energy calculation is calculated using the energy costs of field operations, harvest operations, and inputs on a British thermal unit (BTU) per bushel basis. In the table comparing the model crop systems, the conversion has been made from BTU/bushel to BTU/acre. The most relevant components of the Energy module to our local farming practices are embedded energy in fertiliser and crop protectants such as herbicides and pesticides, field equipment operations, and seed energy. Additionally, in order to accurately reflect management practices, a seeding rate input was necessary. The seeding rates for ARG and meadowfoam are different. The only available crop in this area for FPC was wheat – thus making


Table 2: Comparison of results. Soil Erosion (soil lost – tons/acre)


System 1 NT ARG


NT Meadowfoam NT ARG


NT Meadowfoam NT ARG Totals


System 2 NT ARG


NT ARG NT ARG


Conventional ARG NT ARG Totals


System 3 NT ARG


NT ARG


NT Meadowfoam NT ARG NT ARG Totals


0.1 0.1 0.1 0.1 0.1 0.5


0.1 0.1 0.1 1.0 0.1 1.4


0.1 0.1 0.1 0.1 0.1 0.5


the seed energy level used dependent on the BTU calculation for wheat but with different seeding rates for the ARG versus meadowfoam. So for this study, we assumed away the effects of seed energy usage calculations in the model. In Table 2, energy usages for the different crops are listed exclusive of seed energy.


Soil conservation


Soil conservation ratings measure erosion. Land management practices have a measurable impact on erosion. The soil conservation module of FPC is based upon revised universal soil loss equation, version 2 (RUSLE2)8


prediction system (WEPS)9


and wind erosion formulas.


These USDA designed formulas model erosion in tonnes per acre. RUSLE2 is used to predict the long-term average rate of erosion for combinations of crop systems and management practices. Wind erosion is a component of the soil conservation model.


Water quality Water quality is a function of soil physical properties, nutrient management, tillage systems, and IPM. The water quality index is composed of these measurements which are equally weighted: field physical sensitivity, nutrient management, tillage management, and pest management.


4.81 1.7


4.81 1.7


4.81 17.83


4.81 4.88 4.91 5.48 4.81


24.89


4.81 4.88 1.7


4.81 4.88


21.08


8.67 8.26 8.67 8.26 8.67


42.53


8.67 8.67 8.38 7.75 8.67


42.14


8.67 8.67 8.26 8.67 8.67


42.94


These are each used to create a water quality factor which is then adjusted for irrigation and conservation practices.


Comparisons of results using the FPC


Soil conservation is rated in tons of soil loss per acre. Energy is rated in BTUs per acre excluding seed energy. Water quality is an index rating on a scale of 0-10; the higher the rating numbers the better the water quality rating. Totals are the total accumulated ratings scores or respective units for the five year time period.


Analysis of results We made a decision to begin to measure the impact and sustainability of meadowfoam in our cooperative members’ cropping rotations by initially looking at three key areas: soil conservation, energy use, and water quality. We then set out to answer two questions:  Would the field to market’s fieldprint calculator be able to model and quantify the impacts on the key areas of various cropping systems and agronomic practices that our cooperative members commonly used to produce meadowfoam seed?


 Using these metrics what impact does Reprinted from February 2014 PERSONAL CARE 3 Energy (BTU/acre) Water Quality Index


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