School: Melrose High
Area of Science: Biology
Interim: Team Number: 069
School Name: Melrose High School
Area of Science: Agricultural Science
Project Title: Pasture-ization 2.0
The area of New Mexico that I live in is has very strong agricultural base. Many farms and ranches have been in their respective families for many years. The tradition of caring for the land is as much a part of our culture as it is a good business practice. The area that this project focuses on is ranch management, specifically calculating stocking rates.
Overgrazing is very common in this area. Especially recently, coming out of a severe five year plus drought, many rancher’s pastures have been damaged by overgrazing. Overgrazing is stocking more cattle than a pasture can support, or in other words, exceeding the carrying capacity of that pasture. This can be done in many ways, such as continuous use without sufficient rain, or just plain overstocking. As a pasture loses its protective covering of grasses, it becomes barren and becomes susceptible to erosion.
It can take a pasture that’s been overgrazed many years to recover. An example of this was the Dust Bowl of the 1930’s. When farmers kept plowing and planting year after year without any rain, the land became barren, and began to blow in the harsh plains winds. This is essentially what overgrazing can do to a pasture.
If overgrazed, a ranch can go broke, forcing the owners to sell and move on. For many people in the ranching industry, it is a lifestyle rather than a job. The loss of profit, land, and cattle is devastating to these families.
In this project, I wish to create a program that would allow ranchers to calculate their stocking rates based on their area rainfall, cattle amount, pasture size, and grass type. I do not wish to design this model for complete accuracy, I wish to design it in a way that it would calculate the dates that ranchers need to move cattle off of a pasture a couple weeks in advance of the overgrazing point. I believe this would be a good feature so that the rancher could plan for the move instead of having an “Oh Snap” moment and having to do a last minute move.
Progress to Date
As of now I have started a base model in Netlogo 5.0.4. This has basically been coding in variables and obtaining values of these variables through research. Some of the variables I have coded to date controlled by sliders include: the number of cattle stocked, or CattleCreated; the rate at which grass grows, which I will delete and add a more accurate means by creating procedures for different types of grass; and the amount of grass the pasture starts out with, or StartingGrass%.
I also have three procedures in my model to date. I have a “Setup procedure”, which takes the StartingGrass% value, and the CattleCreated value, and sets up the interface accordingly. My next procedure is the “Calve” procedure, which is only to be used if pregnant cows are being stocked on the pasture. This procedure doubles the amount of cattle originally stocked, to represent calves which will be born while on this pasture. Lastly, my “Go” procedure simulates the normal activities of cattle, such as grazing, chewing cud, or re-digestion, and sleeping.
As of yet I have not done much research. Most of my time has been spent programing this model.
I do not expect to obtain any unchanging results. The results will vary based on the input values, and the input values will be different for every situation. As long as the results gained by this model are within a few weeks before the point of overgrazing, I will have reached my goal. The whole point of this model was to calculate stocking rates and give ranchers a few weeks’ notice before a move.
Team Member: Ethan Wright
Sponsoring Teacher: Alan Daugherty
Doranne Publishing Farm Management Guide
Gillespe Modern livestock and Production
Sponsoring Teacher: Alan Daugherty
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