Cover Crop Use for Managing Broiler Litter Applied in the Fall

Abstract

Increasing interest of using broiler litter in the fall for row crops has implications for leaching losses of nutrients, particularly N. Any cultural practice that prevents nutrient losses could be agronomically beneficial and improve soil fertility. A field study was conducted in 2007 and 2008 on Leeper silty clay loam (fine, smectitic, nonacid, thermic Vertic Epiaquepts) soil to evaluate the impacts of a winter rye (Secale cereal L.) cover crop and broiler litter timing on cotton (Gossypium hirsutum L.) yield, yield components and leaching loss of NO3–N. Broiler litter was applied to the soil at the rates of 0, 4.5, 9, and 13.4 Mg ha−1 in the fall and spring for both cover and no cover crop and incorporated immediately. Winter rye cover crop was planted following broiler litter application in the fall. Averaged across cropping system and broiler litter timing, cotton lint yield and yield components increased with increasing broiler litter application. Application of broiler litter at a rate >9 Mg ha−1 was not advantageous and exceeded N need for optimum lint yield as evidenced by increasing postharvest NO3–N in the soil profile. In the absence of cover crop and averaged across litter rates, spring‐applied broiler litter had the best agronomic response and increased lint yield by 19 and 18% compared with fall‐applied litter in 2007 and 2008, respectively. Seeding a winter rye cover crop to fall‐applied broiler litter did not benefit cotton lint yield and yield components but substantially reduced leaching loss of NO3–N.

Nitrogen Benefits of Winter Cover Crop and Fall‐Applied Poultry Litter to Corn

“…LSD values present to separate means. prior research in which rye biomass production and N uptake increased quadratically with up to 9 Mg ha -1 of PL, with no effect on cotton (Gossypium hirsutum L.) lint (Adeli et al, 2011). In potato (Solanum tuberosum L.), rye had lower N use efficiency compared to forage radish (Raphanus sativus L.) and winter pea (Pisum sativum L.) (Jahanzad et al, 2017).…”

“…However, limited research exists examining fall-applied animal manures coupled with CC and subsequent impacts on crop yield and inorganic fertilizer needs. Adeli et al (2011) noted that although rye sequestered PL N applied in the fall and reduced NO 3 -leaching, there was little effect on cotton (Gossypium hirsutum L.) yield. Rye production responded to increasing levels of residual soil N derived from fertilizer and manure, but generally a subsequent row crop the following season did not benefit from grass-manure systems (Staver and Brinsfield, 1998;Singer et al, 2008).…”

“…Animal manures play an important role in the recycling of nutrients when properly utilized in row crop production systems and can serve as a substitute for inorganic fertilizer inputs. As with fertilizers, manure derived N and P can become environmental pollutants when availability is asynchronous with crop demand or rates are excessive (Andraski et al, 2000;Sharpley et al, 2007;Adeli et al, 2011). Current row crop production practices are heavily reliant on inorganic fertilizer sources (Hera, 1996), which have experienced fl uctuations in pricing and an overall increase in cost in recent years causing growers to seek other nutrient source options such as manure.…”

“…In the mid-South, PL applications may occur following crop harvest in the fall, as it is a period which is operationally favorable and more easily coordinated with logistics of trucking and spreading. Growers are primarily interested in PL benefi ts of added organic matter, P, and K, while assuming zero credit for PL-derived N due to potential overwinter N losses, especially by leaching (Adeli et al, 2011).…”

“…Non-legume winter CC such as rye are known to reduce leaching losses of nitrate N (NO 3 --N) derived from organic sources such as manures and legumes, as well as from inorganic fertilizers (Adeli et al, 2011;Ditsch et al, 1993;Staver and Brinsfi eld, 1998). Studies on N dynamics in legume cover crop systems have indicated the importance of the associated C in immobilizing legume N in the organic matter fraction of soil (Ladd et al, 1981;Varco et al, 1993;Harris et al, 1994;Seo et al, 2006).…”