1a. Objectives (from AD-416)
Evaluate the long-term effect of soil organic carbon (SOC) on soil quality: 1)To determine the amount and types of carbon accrued in long-term field plots; 2)To evaluate the effects of tillage practice, winter cover cropping, compost application, soil depth and soil aggregate size fraction on total SOC and SOC constituent contents; 3)To relate total SOC and SOC constituent contents with soil structural stability and erodibility; 4)To determine total SOC content level and constituents most effective at increasing soil stability and reducing soil erodibility; and 5)To identify agronomic practices that effectively increase soil stability and decrease erodibility.
1b. Approach (from AD-416)
Soil quality will be evaluated in university controlled long-term piedmont and coastal field plots that have treatments of no-tillage, no-tillage with winter cover and compost, disk tillage, and disk tillage with winter cover and compost. In each treatment, soil organic carbon (SOC) will be analyzed for particulate carbon, labile carbon, microbial biomass, total soil carbohydrates, and glomalin. SOC components will be related to mineralization, respiration, and aggregate stability. Testing for aggregate stability include wet sieving, dry sieving, and rainfall simulation of selected aggregate sizes analyzing runoff and splash.
3. Progress Report
This project is related to inhouse objective 1. Develop specifically designed biochar or biochar mixtures that amend sandy SE coastal soils to increase aggregation, improve nutrient retention, sequester organic carbon, improve microbial characteristics, and decrease overall soil strength. Samples were taken from long-term piedmont and coastal field plots treated with no-tillage, no-tillage with winter cover and compost, disk tillage, and disk tillage with winter cover and compost. Samples were analyzed for soil organic carbon, more specifically particulate carbon, labile carbon, microbial biomass, total soil carbohydrates, and glomalin. Treatments were also subjected to rainfall under a rainfall simulator to measure runoff and splash. Progress was monitored by occasional visits to the North Carolina A&T campus, emails, and phone calls.