The McLean County Soil Erosion and Cropland Tillage Transect Survey
The Illinois Department of Agriculture, in cooperation with Illinois Soil and Water Conservation Districts, completes a Soil Erosion and Cropland Tillage Transect Survey. The survey aims to gather more information about the implementation of conservation farming practices, and to assess the condition of McLean County. Tillage data is gathered for corn and soybeans, and the county’s T levels are assessed. “T” represents the tolerable soil level loss, or the amount of soil that can be replaced naturally by the decomposition of crop residue. In addition to T levels and tillage data, the survey compiles some information on cover crop use.
Agricultural runoff is a significant source of phosphorous and nitrate-nitrogen loading into Illinois waterways. Nutrient runoff is carried by the rivers and streams to the Mississippi, and down to the Gulf of Mexico. Nutrient concentration in the Gulf of Mexico is so high that it causes algal blooms, and subsequent dead zones called “hypoxic zones”, devoid of life. To combat this issue and promote soil health and water quality, Illinois’ Nutrient Loss Reduction Strategy (NLRS) was created. The NLRS aims to direct efforts to reduce nutrients from point and non-point sources. The goal is for Illinois to reduce its phosphorous load by 25% and its nitrate-nitrogen load by 15% by 2025. The eventual target is a 45% reduction in the loss of these nutrients to the Mississippi River.
Some conservation practices that help reduce nutrient runoff include cover crops, filter strips and buffers, conservation tillage (no-till, strip-till, etc.) and habitat projects, such as pollinator habitat and constructed wetlands .
McLean County Illinois Transect Survey Results
The latest McLean County Transect Survey was conducted on 501 McLean County field locations. Comparable to prior surveys these results suggest a large reduction in conventional tillage and increase in no-till and mulch tillage practices. Results on corn acres showed 32% Mulch Till, 31 % Reduced Till, 28 % Conventional, and 9% No-till. Soybean acres resulted in 58% Mulch Till, 35% No-till, 5% Reduce Till, and 2% Conventional. The cumulative figures were as follows: 501 locations measured, 112 No-Till fields, 221 Mulch Till fields, 82 Reduce Till fields, and 66 Conventional fields. Less than 1% of the fields contained Cover Crop residue.