The emergence of strip-till (ST) as an alternative to no-till (NT) provides corn (Zea mays L.) and soybean [Glycine max. (L.) Merr.] producers with a management practice which has benefits similar to conventional tillage systems without the drawbacks common to NT in the typical wet and cool early-spring conditions of Illinois. Recent research in Illinois suggests that greater yield with ST than NT for corn and soybeans could be explained by differences in root characteristics and enhanced nutrient uptake in ST. However, the effect of ST compared with NT practices on soil properties in Illinois remains unclear. Additionally, corn yield has been shown to decrease as variability increases and research suggests greater variability under NT, yet differences in variability between ST and NT have largely not been quantified. The objectives of this study were to: i) evaluate specific soil properties (soil organic matter, penetration resistance, bulk density, water aggregate stability, infiltration rate) that could be influencing the differences in root efficiencies and nutrient uptake observed under ST and ii) determine if variability differs between ST and NT for linear distance between plants, plant height, stalk diameter, dry biomass accumulation, number of barren ears, and grain yield and yield components. Tillage treatments of NT and ST were arranged in a randomized complete block design with 3 replications on two adjacent fields in a corn – soybean rotation. These treatments were established in 2007 as part of a long-term study. The effect of tillage (NT, ST) on soil properties at four different positions relative to the crop row and at four successive depths were measured during the corn phase in each field in 2012 and 2013. Variability measurements of individual plants were taken from all plants present within a 1.5 m length row section from rows three and six of each 8-row plot. I also calculated plant spacing variability, area occupied plant-1, and plant population. Soil properties were generally improved in ST compared with NT. Specifically, ST improved soil organic matter, and reduced bulk density and penetration resistance in the surface 10 cm relative to NT. Yet, I found no differences between tillage treatments in water aggregate stability at the crop row, but increased water aggregate stability in NT at the inter-row. While ST increased yield in previous years, tillage system did not influence corn yield during the two years of the study likely due to extreme differences in temperature, precipitation, and planting date between the two growing seasons. Similarly, no tillage treatment differences were observed for water Inf. Tillage treatments had no significant impact on any of the plant-to-plant variability variables measured. The lack of significance between tillage treatments on variability measurements is likely the result of substantial stress for normal crop growth and development caused by drought conditions in 2012 and cool wet conditions in 2013, which delayed planting. Our results suggest that ST improves soil properties of the surface soil compared with NT, which could explain previous research results showing enhanced root growth, nutrient uptake, and corn and soybean yield under ST. Variability measurements are both instructive and descriptive and may prove useful for future studies.
【 预 览 】
附件列表
Files
Size
Format
View
A comparison of soil properties and plant-to-plant variability in no-till and strip-till corn fields in Illinois
PDF
download
878987797
028-85220240
