No-till rice and soybean production is not a common practice in Arkansas. With rising fuel costs and an interest in carbon sequestration, there is a possibility that no-till will become more popular in the future. This will no-doubt happen if there is a market for sequestered carbon, and farmers receive reasonable payments for no-till practices.
One of the most common reasons farmers give for not practicing no-till crop production is that they fear grain yields and profitability will decline. Switching to no-till management is confounded with rice production in that there are a number of field operations that are needed to provide adequate water management and that those operations oftentimes are different for soybeans than for rice.
In 2000, we initiated a study at the Rice Research and Extension Center that compares grain yields in a no-till, rice-soybean rotation to a similar conventional-till rotation. Both tillage systems use the same varieties, fertilizer levels and pest and disease control measures. They are planted and harvested at the same time with the same equipment. Two varieties are used each year with Wells having been used in every year of the study. Each plot is divided into two fertility levels; one representing a lower application rate and the other a higher application rate.
No-till rotation will work in Arkansas
When comparing tillage treatments, no treatment was better in all years. However, there was a trend of increasing grain yields in the no-till plots as the study got older. Initially, rice grain yields were lower in the no-till plots when compared to the conventional-till plots. This same trend has been documented for a number of crops and was expected here.
Further analysis of these data has shown that, over all years, there was less variation in the no-till rice grain yields as compared to the conventional-till yields. Stability in the no-till rice grain yields makes this management system attractive to farmers who are adverse to high risk.
Soybean grain yields have steadily increased over the eight years of this study. This is attributed to the availability of higher yielding soybean varieties. We have documented improvements in soil quality and reduced water and plant nutrient runoff from the no-till compared to conventional-till. When we put these data with the grain yield data, it is evident that a no-till approach to rice-soybean production has a good future. To better facilitate farmers’ knowledge of this work, we are preparing Extension publications, available in late 2009, that will cover how to manage a no-till rice-soybean rotation, economic benefits of a no-till rice-soybean rotation and natural resource benefits from a rice-soybean rotation.
Merle Anders is a rice systems agronomist with the U of A Division of Agriculture.