Soil loss may one of the most damaging aspects of production agriculture. It has a tremendous effect on both soil health and water quality. Under the best case scenario, soil can only rebuild at a rate of 0.24 tons per acre per year. When you’re losing soil, you’re losing both yield and money.
This information should raise some important questions.
Do you know how much soil you are losing from your farm?
Judging soil loss is difficult, as indicated by a recent survey among farmers. The survey showed 42% of farmers estimated that they averaged less than 1/4 ton per acre annual soil loss in 2016, with another 38% saying 1/4 to 1 ton per acre. However, to achieve such an extremely low erosion rate, you’d have to be doing zero tillage on a nearly flat field.
The average soil loss rate is more than 5 tons per acre per year based on The Revised Universal Soil Loss Equation. This is a tool that calculates soil loss based on soil loss factors. The equation is A=R*K*LS*C*P
A = tons soil per acre per year
R = rainfall and runoff factor
K = soil type erodiblity factor
LS = slope factor (length and steepness)
C = crop and cover management factor (Compares crop rotations, tillage, and % cover residue at planting)
P = conservation practice factor (contour and or strip cropping).
Each of these 5 factors affect the amount of soil lost by erosion. The first 3 are a given including soil type, slope, and weather. There is not a lot we can do to change them. However we can make changes to the last 2 factors.
The changes we make in crop and cover management and conservation practices will either increase or reduce soil loss. Crop and cover management includes crop rotation, tillage, and cover crops. Conservation practice factor includes farming on the contour, and or strip cropping. Over the last several years we have seen changes in crop production management systems. There may be good reasons for these changes but the result is an increased risk of erosion and soil loss. Less small grain and hay in crop rotations, larger equipment resulting in loss of contour strips, increased tillage, and more intense rain events may be increasing soil loss from our fields.
What is the cost of a ton of soil loss?
This cost may not be obvious but it is real. Based on a recent call to a local contractor a ton of top soil will cost you around $20 delivered. Also keep in mind that when you are losing soil you are losing yield. Research from Iowa and Missouri indicates this yield loss potential could be as high as 15 bushels per acre per year. You are also losing valuable nutrients attached to the soil that you will have to replace.
Do you know how much soil loss is occurring on your farm and what is the cost to your operation?
If you don’t know, it is difficult to do something about it. Holmes SWCD can help find answers for your operation using The Revised Universal Soil Loss Equation.
What can you do to prevent the loss of top soil?
- No till or reduced tillage. This will maximize the residue on top of the ground and improve soil structure resulting in less top soil moving off your fields.
- Cover crops. There are many benefits to cover crops but reducing soil loss ranks at the top of the list. A cover crop can protect your soil during the time between cash crops.
- Crop rotation. Adding small grain or hay to your rotation will function like a cover crop and may allow for more cover crop options.
We all know there is a cost associated with each of these practices. No till may yield less for a few years. Covers crops cost money to plant. Corn/soybean rotation may be more profitable than adding wheat or hay. But there is also a cost to losing your top soil. So the next question is:
What are the costs for my operation?
With tight profit margins you may be reluctant to spend more money even on practices that reduce soil loss. I understand. But if you save the money by not spending on these practices you will risk the costs of soil loss. Do you want to invest in practices that save your top soil or pay for the cost of erosion and soil loss? You get to choose.
You don’t have to make all the changes at once. Think of it as big sandwich. Plan to take a small bite every year by planting a cover crop on 20% of your acres. Or add wheat or hay to 20% of your acres each year. Or you may want to try no till or minimum tillage on some of your fields.
In summary, make a commitment to preserving the top soil and guarding against the future cost of replacing it. That commitment can result in keeping your soil where it belongs.
Joe Christner came to Holmes SWCD in 2001 with experience and knowledge drawn from 20-plus years of dairy farming. He grew up on a small farm near New Bedford, Ohio. His background interest and involvement in agriculture from the time he was a young man give him an empathy and understanding of the needs and concerns of today’s farmers. Joe can assist you with conservation plans for your farming operation, including nutrient management planning and record keeping. Water quality, soil health, and conserving the resources needed for the next generation and beyond is very important to Joe.
Contact Joe at 330-674-2811 or firstname.lastname@example.org