Does it pay? As noble a goal as crop rotation might be, this is the question that growers must answer before making a crop rotation decision.
Studies throughout the Southeast have shown that both cotton and peanut yields may be increased by utilizing recommended crop rotation systems.
“A good rotation system will add organic matter to infertile soils for better nutrient and water-holding capacity, will lower compaction and reduce pest levels,” says Tim Hewitt, University of Florida Extension economist. Hewitt is one of several researchers involved in a four-state project examining the economic benefits and consideration of cotton rotations in the Southeast.
In addition to Florida, Georgia, North Carolina and Alabama also were involved in the study.
In some cases, says Hewitt, the economic benefits of rotation were not evident. But overall — in the Southeast — both yields and economic returns improved with crop rotation.
“In Florida and Georgia, yields for cotton and peanuts have improved by as much as 25 percent due to rotations,” says Hewitt. “Economic returns increased by more than 15 percent in the two states in some experiments and on-farm studies.”
Alabama results also have shown positive returns — of 10 percent — due to rotations, he adds. “However, a six-year rotation in North Carolina has shown that continuous cotton has a higher per-acre return than the rotation systems.
“This is due partly to higher production costs and low prices for other commodities. Cotton production costs vary throughout the Southeast. In some areas, crop rotations actually may decrease per-acre production costs,” he says.
Some of the studies, says Hewitt, indicate that costs are increased but are more than offset by increased yields. Labor constraints also should be considered in any crop rotation decision, he says.
“Individual operations may be limited in which type of production system to use by labor availability,” notes the economist. “Producers need to carefully consider rotation systems as a way to maintain or increase profits and improve soil and cropping conditions.”
Choices among rotational systems often are more dependent on local agronomic and management considerations than on yield increases and rotational profitability.
Cotton acreage has increased substantially in the Southeast since the early 1990s, due primarily to changes in farm programs and relatively low prices of other commodities that have been grown in the region. Cotton, along with peanuts, has been more profitable than other crop options in the South.
“As production has shifted to increased acreage of cotton and peanuts, yields have suffered due to poor rotations that cause pest and other cultural problems,” says Hewitt. “The lack of profitable rotation crops has forced many producers to plant cotton in short rotations or to plant continuous cotton.”
Profits are more likely, he says, for those producers who grow cotton and peanuts than for those who must use other crops in rotation with cotton.
Much research has been conducted to look at the benefits of rotations for cotton. Most rotation studies, says Hewitt, address only agronomic benefits by comparing yield responses to various treatments. Previous studies, he adds, concluded that crop rotations produced substantially higher cotton yields than continuous cotton systems in the first year of the study.
A Texas A&M study compared rotations, tillage systems, and fertility levels on cotton yields. The study evaluated cotton-corn, corn-cotton,, soybean-cotton, and continuous cotton. The tillage treatment had no effect on yield response, and the yield advantage of the different rotations fluctuated widely each year.
“Rotation is critical for successful cotton production since the crop is susceptible to numerous pest problems that reduce yields,” says Hewitt. “Finding ways to reduce costs also is important as input costs continue to increase without significant price increases for cotton.”
The question that must be answered is whether or not a crop rotation is profitable. “Producers must analyze the research results and experiment on their farms to answer the ‘does it pay’ question. Knowing the long-term financial implications of adapting different crop rotations is critical.”
Summaries of the four-state rotational studies are as follows:
Georgia — Research was conducted on farms in Georgia over four years to look at economic considerations and nematode management.
Including both corn and soybeans in the rotation improved yields but not necessarily returns. This is due to higher per-acre costs and poor prices for soybeans. This data indicates that a cotton-corn rotation appears to be a profitable alternative to continuous cotton.
North Carolina — Model farms were developed in three counties in eastern North Carolina. Actual yield and price data were utilized in budgets to simulate risks for adapting different crop rotations. In this study, the model farms showed very different results for the crop rotations. The net farm income with the rotations was not as high as the income for continuous cotton. This study illustrates that improved yields alone do not translate into higher net farm income — agronomic benefits also must be weighed.
Florida — Rotation studies have been done in Florida that results in an increased yield for rotations and higher average returns for rotations. Sod-based rotation studies also have been researched that indicate the addition of some type of sod has yield benefits.
The addition of sod has reduced soil-borne diseases and helped in improving agronomic cultural practices. Nematode problems also are improved by utilizing a good rotation scheme. Crop yields were improved by more than 20 percent, and net incomes also improved with rotation.
Alabama — Seven corn-peanut-cotton rotations were evaluated during a six-year period beginning in 1997 in southeast Alabama. The treatments ranged from continuous peanuts to continuous cotton. Plot yields were converted on an acreage basis, and costs from Extension budgets were applied. Returns per acre were calculated, with the assumption that seed sales covered ginning costs in the case of cotton, and that handling charges were included in the price for peanuts.
Results in agronomic terms demonstrated the advantages of crop rotation. The average lint yield for plots containing cotton was more than 9 percent higher than the average for plots with continuous cotton. The average lint yield for the best cotton rotation was more than 24 percent higher than the average for plots in continuous cotton. The results for peanuts were even more striking. The average yield for peanuts in plots containing a cotton rotation was 19 percent higher than the average for plots with continuous peanuts. The highest yielding rotation for peanuts was more than 35 percent higher than continuous peanuts.
However, over the six years of the study, the continuous plots for both cotton and peanuts produced the most, ranking first by a considerable margin. This is natural considering they produced the appropriate crop each year. This demonstrates the economic basis for the reluctance of farmers to rotate land where an alternative - comparably profitable — enterprise is not apparent. In this analysis, the break-even production level of cotton and peanuts over variable costs was 513 and 2,338 pounds, respectively. Break-even production over total cost was 669 pounds of cotton lint and 3,117 pounds of peanuts.
These tests, says Hewitt, demonstrate the advantages of crop rotation production when profitable alternatives exist. The results also demonstrate that the choice among rotational systems probably is more dependent on local agronomic and management considerations than on yield increases and rotational profitability.
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