@article{jordan_barnes_bogle_naderman_roberson_johnson_2001, title={Peanut Response to Tillage and Fertilization}, volume={93}, DOI={10.2134/agronj2001.9351125x}, abstractNote={Peanut ( Arachis hypogaea L.) in the USA is generally seeded after several primary tillage operations that may include disking, chisel plowing, moldboard plowing, and bedding (conventional tillage systems). Concerns over erosion and production costs have increased interest in reduced tillage systems. Production in reduced tillage systems minimizes ability to incorporate fertilizers below the pegging zone, and residue on soil surface could impact movement of calcium sulfate (CaSO 4 ) into the soil, reducing Ca availability to pegs. Research was conducted from 1997 through 1999 to compare peanut yield and gross economic value of virginia market type peanut planted in conventional and strip tillage systems. Preplant fertilizer did not affect response to tillage. Response did not differ among conventional tillage systems consisting of disk, disk and chisel, or disk and moldboard plow or among reduced tillage systems. Pod yield of peanut grown in the most effective conventional tillage system exceeded yield when peanut was strip‐tilled into stubble of the previous crop, strip‐tilled into a wheat ( Triticum aestivum L.) cover crop, or strip‐tilled into beds prepared the previous fall without a cover crop. Tillage system and CaSO 4 rate affected pod yield and gross value independently. Gross value increased when CaSO 4 was applied regardless of tillage system. These data suggest that preplant fertilizer at relatively low, remedial rates does not affect peanut response to tillage systems. These data also suggest that tillage system does not have a major impact on peanut response to CaSO 4 . Collectively, these data indicate that the highest peanut yields occur in conventional tillage systems.}, number={5}, journal={Agronomy Journal}, author={Jordan, David L. and Barnes, J. Steve and Bogle, Clyde R. and Naderman, George C. and Roberson, Gary T. and Johnson, P. Dewayne}, year={2001}, month={Sep}, pages={1125–1130} }
 @article{crozier_naderman_tucker_sugg_1999, title={Nutrient and pH stratification with conventional and no‐till management}, DOI={10.1080/00103629909370184}, abstractNote={Abstract This study investigated changes in soil test results associated with sampling depths in fields managed with conventional tillage, no‐till for less than 3 years, no‐till for 3 to 6 years, and no‐till for more than 6 years. Soil samples from depths of 0–5, 0–10, 0–20, and 10–20 cm were collected from 59 fields with different tillage histories from several geologic regions, and analyzed by the North Carolina Department of Agriculture soil test laboratory. Some nutrient stratification was noted in all tillage categories. Soil test phosphorus (P), potassium (K), and zinc (Zn) concentrations were significantly higher in the 0–10 cm depth than in the 10–20 cm depth. Stratification probably results from the prevalence of tillage with disks, chisel plows or subsoilers, which do not mix the soil thoroughly. With the adoption of no‐till methods, stratification becomes even more pronounced. Our data suggest that stratification in pH, calcium (Ca), manganese (Mn), and sulfur (S) is more likely for fields in the early stages of no‐till (less than 6 years) than in longer‐term no‐till. In fields managed with no‐till for less than 3 years or for 3 to 6 years, pH and Ca, Mn, and copper (Cu) concentrations were higher and the S concentration was lower in the surface 0–10 cm layer than in the underlying 10–20 cm soil layer. These differences were not significant for fields managed with no‐till for more than 6 years or with conventional tillage. In fields with low P or K levels, higher nutrient concentrations near the surface result in lower fertilizer rate recommendations with shallower sampling depths. The overall pH effect across geologic regions was very small, generally 0.1 to 0.2 pH unit, so lime recommendation did not vary significantly with sampling depth in most cases. For monitoring changes in plant nutrient and heavy metal concentrations over time, sampling no‐till fields requires even more attention to depth than for conventionally tilled fields.}, number={1/2}, journal={Communications in Soil Science and Plant Analysis}, author={Crozier, Carl R. and Naderman, George C. and Tucker, M. Ray and Sugg, Roger E.}, year={1999}, month={Jan} }