Economics of Conservation Tillage Systems for CRP Land in Southern Illinois

A tillage project was initiated in 1989 at the University of Illinois Dixon Springs Agricultural Research Center in southern Illinois to evaluate conservation tillage systems for land being removed from Conservation Reserve Program (CRP). No‐till (NT), chisel plow (CP), and moldboard plow (MP) tillage systems on a Grantsburg silt loam (fine‐silty, mixed, mesic Typic Fragiudalf) soil were studied. The soil has a fragipan at approximately 26 in. below the surface on a 6.5% east facing slope. The tillage treatments were replicated eight times on 30 by 40 ft plots. The area had been in tall fescue [ Festuca arundinacea (L.) Schreb.] sod. For the project, corn ( Zea mays L.) and soybean [ Glycine max (L.) Merr.] were grown on a 6‐yr rotation. Economic data were estimated for the three tillage systems using a simulation model to select equipment and estimate costs. The objective was to determine crop yields and to compare returns of the tillage treatments applied to CRP sod. Based on 6 yr of crop yield measurements (3 yr corn and 3 yr soybean), NT and CP systems appear to result in improved long‐term productivity of sloping soil compared with MP. Machinery requirements and costs were lower with NT than with the two other tillage systems. MP had the greatest machinery requirements and highest costs and highest corn yield only in 1989. Crop yields with the NT system improved compared with the yields with MP and CP systems each year with NT resulting in the highest crop yield in the fourth, fifth, and sixth years with the differences statistically significant the last two crop years. The NT system provided the highest net income and the MP system the lowest over the 6 yr study. Net income with NT system was $32/acre per yr higher than with the CP system (simple average without time valuation adjustment) and $40/acre per yr higher than with the MP system. The NT system reduced soil loss from erosion to below the current and future soil loss standards. Research Question The Food Security Act of 1985 and the 1990 Farm bill have resulted in millions of acres of erodible land previously in row crops being put into the Conservation Reserve Program (CRP). It is not known how long this program will be continued or what will happen to the land when it is released. Any conversion of CRP land back to corn and soybean production could require conservation tillage systems such as no‐till and chisel plow to meet soil erosion standards. Most farmers accept the fact that conservation tillage systems significantly reduce soil erosion and desire to adopt such systems. The primary concerns of farmers considering the switch to conservation tillage are the effects on crop production and profitability. The objectives of this study were to determine crop yields and to compare net income of the conservation tillage treatments with the moldboard plow system when applied to sloping and eroded CRP land in sod. Literature Summary Goals of sustainable agriculture include reduced soil erosion, maintenance and restoration of crop productivity, reduced pollution of ground and surface water, and farm profitability. A major means of accomplishing these goals is the widespread adoption of conservation tillage, in which significant levels of crop residue remain on the soil surface to reduce soil erosion. Complementary to the erosion control goals of sustainable agriculture are the conservation compliance provisions of the Illinois T by 2000 program, the U.S. Food Security Act of 1985, and the 1990 Farm bill. These federal and state acts require conservation measures be used on land classified as highly erodible. A major conservation measure to be used to meet compliance is conservation tillage. New computer programs compare alternative farming methods on the basis of costs of machinery, herbicides, fertilizers, and other crop inputs that aid in the farm sector's decision making. One Illinois computer program was designed to assist in selecting a low cost set of machinery for a farm. It schedules the desired field operations and calculates all machinery related costs. Computer programs and economic budgeting worksheets provide efficient methods for determining profitability of different tillage systems. Study Description This tillage project was initiated in 1989 at the University of Illinois Dixon Springs Agricultural Research Center in southern Illinois. The effects of no‐till (NT), chisel plow (CP), and moldboard plow (MP) tillage systems on a Grantsburg silt loam soil were studied. The tillage treatments were replicated eight times on 30 by 40 ft plots. For the project, corn and soybean were grown on a six‐year rotation. Prior to the establishment of the experiment, the area had been a tall fescue hayland, similar to CRP land, for more than 10 yr. The experimental design allowed for randomization of tillage treatment (NT, CP, and MP) both by row (block) and by column (replication) to control random variability in both directions. This paper summarizes crop yield and economic data for the three tillage systems with actual inputs used on the plots. The objectives of this study were to measure the crop yield, estimate machinery‐related costs, and compare the returns of W, CP, and NT systems applied to CRP, sod on sloping and eroded soils. Applied Questions Do conservation tillage systems maintain crop yield over time as well as moldboard plow system on sloping and eroding soils? Yes. The grain yield × year, crop and treatment are provided in Table . In 1989, corn grain yield for NT was significantly lower than for either MP or CP. Corn yield with CP was also significantly lower than with MP. The initial yield advantage for the MP system the first year did not occur the last 5 yr. The NT system crop yield improved relative to the MP system each year and NT had the highest crop yield the fourth, fifth, and sixth years with the differences statistically significant in the last two crop years. Are conservation tillage systems as profitable over time on sloping and eroding soils as the moldboard plow system? Yes! This six‐year corn‐soybean rotation tillage project at Dixon Springs examined the economics of three tillage systems as if applied to a 1000 acre farm in southern Illinois. Limiting the tillage operations of CP and MP treatments to spring increased machinery and labor costs because of the time constraints. In this study (Table ), NT had the highest net returns and lowest labor requirements, while MP had the highest machinery and labor requirements. Equipment capital requirements were about 50% less for NT than for CP and MP systems. The higher NT herbicide rates were offset by reductions in machinery and labor costs. Over the 6 yr, NT had $4O/acre per yr higher net income than MP and $32/acre per yr higher net income than CP. CP net income was $8/acre per yr higher (simple average without time valuation adjustment) than MP as a result of lower machinery costs. A farmer may revert to performing the primary tillage operations in the fall with CP and MP systems to lower machinery costs; however, this would increase soil erosion above tolerable soil loss limits due to greater exposure of soil to rainfall and wind. Recommendation The NT system provides the farmer with the highest net income over time while reducing soil loss from erosion to below future soil loss standards. Crop yields by treatment per acre per year. Year Crop Treatment Yield, bu/acre 1989 Corn NT 134a 1989 Corn CP 148b 1989 Corn MP 167c 1990 soybean NT 39a 1990 soybean CP 43a 1990 soybean MP 44a 1991 Corn NT 98a 1991 Corn CP 91a 1991 Corn MP 97a 1992 soybean NT 61a 1992 soybean CP 51a 1992 soybean MP 59a 1993 Corn NT 176a 1993 Corn CP 172ab 1993 Corn MP 164b</j