Multi-Cropping Cattle and Watermelon in the Southern Plains
Cattle and watermelons are grown extensively throughout the southern United States. Some farmers produce both commodities, but no one produces both crops on the same land in the same year. Farm diversification with cattle and watermelons would improve cash flow, minimize risks and lead to farm stability and sustainability.
The main disadvantage to cow-calf operations is that the income from small and medium sized cattle farms is not sufficient to maintain a desirable standard of living. Most farms in southeastern Oklahoma are 100 to 300 acres in size, and normally produce about $10,000 to $50,000 of gross farm income, with net profit being a fraction of the gross income.
Watermelons can produce gross returns in excess of $1000 per acre. While watermelons normally produce more income per acre than do cattle, much of the land planted to watermelon is subject to erosion when not kept under a plant cover. Watermelons should be grown in a given field no more than 1 out of 4 years to prevent soil-borne diseases that will reduce, or eliminate, crop yields. Because of this, watermelon growers need access to at least four times the amount of their annual watermelon acreage. Pasture land is unlikely to have a watermelon disease problem, and is thus desirable as a site for rotation with watermelons. However, most cattle farmers are unwilling to convert a permanent pasture into watermelons, and then re-establish the pasture after melon harvest is completed.
Most agriculture in southeastern Oklahoma involves cow-calf operations. Rainfall and temperatures are conducive to grass production, and markets are available throughout the year. Cattle production is also desirable from an environmental standpoint. Cultivated soils in the area are highly erodible by both wind and water, but permanent pastures keep vegetation on the soil and thus greatly reduce soil erosion. In Texas, watermelon producers can plant earlier and harvest later than can those in Oklahoma. This allows more flexibility in designing a multi-cropping system than could be done in Oklahoma.
A system is needed that would allow melon production in an established pasture or meadow for one year without damaging the stand of grass for the following years. An even better system would allow for production of both pasture grasses and watermelon on the same land in the same year. The purpose of this project has been to determine if watermelon and bermuda grass pastures can be grown in the same field in the same year. One approach to answering this question was to grow watermelon in strips in a perennial pasture or meadow. Only a small portion of the pasture was tilled and planted with melons, and the pasture was then allowed to return to grass. With this system, cattle producers can diversify their operations, minimize risk, and improve farm profits. Watermelon producers can reduce soil erosion and have a disease-free site for crop rotation.
Research has been conducted for three years in Oklahoma and Texas to develop such a system. Fields of bermuda grass have been used to grow both hay and watermelons. One technique has been to plant watermelons in the field as early as possible in the spring. Hay is grown between the plots at the same time, and after the melons are harvested, the entire field is allowed to revert to bermuda grass. Another technique is to get one cutting of hay from the field in the spring, and then after the hay is harvested, to plant strips of watermelon into the grass stubble. Grass is allowed to grow between the strips while the watermelons are being grown. The main difference in these two techniques is the timing of harvest for each crop. The first technique involves harvesting watermelons prior to hay, while the second technique involves harvesting hay prior to watermelons. Either technique has potential, and the choice of techniques is primarily dependent upon the market that watermelon growers are attempting to meet.
After three years, we have demonstrated that both hay and watermelon can be harvested from the same field in a single year. The tilled strips that were planted with watermelons in one year may be covered with bermuda grass later during the same year, and will certainly be covered with grass the following year. We have not encountered a noticeable change in either insect or disease occurrence with any of the treatments in this system.
After three years of research, the main limitation to watermelon growth seems to be weed control. Bermuda grass may be classified as a weed when it interferes with watermelon production, even though it is also classified as a crop when grown between the tilled strips or when it is grown before or after the crop of melons. If grasses are completely controlled in the tilled and planted row, broadleaf weeds may become a problem within the row.
One other concern that needs to be further investigated involves pollination of the watermelon. Observations in both Texas and Oklahoma have led us to believe that there may be insufficient pollination. This observation was particularly noticeable in 1998. If insufficient pollination did occur, there are two likely explanations. The first is that there may have been insufficient numbers of bees. During the past two or three years, there has been a dramatic decline in the number of native bees throughout the entire country, including Texas and Oklahoma. A reduced number of bees could have led to insufficient pollination. A second explanation, assuming that the number of bees was sufficient, was that the watermelon flowers were masked by surrounding grasses, and thus did not attract a sufficient number of bees per flower. A third explanation is that the extremely high temperatures that occurred during the time of fruit set in 1998 were detrimental to fruit set, even if a sufficient number of bee visits did occur. Further investigation is needed to determine the cause of low fruit set which occurred in 1998.
The benefits expected from this project have been achieved. The system that has been developed will allow multi-cropping of both bermuda grass and watermelon. This system combines the advantages of a perennial crop with an annual crop. The system encourages crop diversity, and utilizes the advantages of crop polyculture. The system allows the production of a crop that is normally grown by clean culture without subjecting vast amounts of soil surface to erosion by wind or water. The system allows crop rotation within a given field, and thus lessens the chance of pathogen or parasite accumulation. The system allows production of a high value horticultural crop and a perennial soil-covering forage from one field in one year.