Organic producers in the mid-Atlantic region of the USA are interested in reducing tillage, labor and time requirements for grain production. Cover crop-based, organic rotational no-till grain production is one approach to accomplish these goals. This approach is becoming more viable with advancements in a system for planting crops into cover crop residue flattened by a roller–crimper. However, inability to consistently control weeds, particularly perennial weeds, is a major constraint. Cover crop biomass can be increased by manipulating seeding rate, timing of planting and fertility to achieve levels (>8000 kg ha−1) necessary for suppressing summer annual weeds. However, while cover crops are multi-functional tools, when enhancing performance for a given function there are trade-off with other functions. While cover crop management is required for optimal system performance, integration into a crop rotation becomes a critical challenge to the overall success of the production system. Further, high levels of cover crop biomass can constrain crop establishment by reducing optimal seed placement, creating suitable habitat for seed- and seedling-feeding herbivores, and impeding placement of supplemental fertilizers. Multi-institutional and -disciplinary teams have been working in the mid-Atlantic region to address system constraints and management trade-off challenges. Here, we report on past and current research on cover crop-based organic rotational no-till grain production conducted in the mid-Atlantic region.

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Poultry litter provides a rich nutrient source for crops, but the usual practice of surface-applying litter can degrade water quality by allowing nutrients to be transported from fields in surface runoff while much of the ammonia (NH3)-N escapes into the atmosphere. Our goal was to improve on conventional titter application methods to decrease associated nutrient losses to air and water while increasing soil productivity. We developed and tested a knifing technique to directly apply dry poultry litter beneath the surface of pastures. Results showed that subsurface litter application decreased NH3-N volatilization and nutrient losses in runoff more than 90% (compared with surface-applied litter) to levels statistically as low as those from control (no litter) plots. Given this success, two advanced tractor-drawn prototypes were developed to subsurface apply poultry litter in field research. The two prototypes have been tested in pasture and no-till experiments and are both effective in improving nutrient-use efficiency compared with surface-applied litter, increasing crop yields (possibly by retaining more nitrogen in the soil), and decreasing nutrient losses, often to near background (control plot) levels. A paired-watershed study showed that cumulative phosphorus losses in runoff from continuously grazed perennial pastures were decreased by 55% over a 3-yr period if the annual poultry litter applications were subsurface applied rather than surface broadcast. Results highlight opportunities and challenges for commercial adoption of subsurface poultry litter application in pasture and no-till systems.

All rights reserved. No part of this periodical may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. C otton is an essential source of natural fi ber. For every 100 kg of lint fi ber ginned from cotton, 150 kg of cottonseed is produced (Yu et al., 2012). Whole cottonseed and its products can be used as human food, animal feed, and industrial raw materials. For example, cottonseed oil is used as edible oil in food processing and restaurants (O'Brien and Wakelyn, 2005), and has the potential to be used as biofuel (Meneghetti et al., 2007). Whole seed and cottonseed meal are valuable dairy feedstuff (Arieli, 1998; Bertrand et al., 2005). Although not widely used, cottonseed meal can be used as an adhesive for wood-gluing applications (Hogan and Arthur, 1951; Lambuth, 2003). Th e chemical composition is an important parameter in evaluating cottonseed quality for diff erent applications. Genetic, environmental, and agronomic approaches have been used to alter cottonseed composition (Cherry et al., 1978). Cottonseed oil and protein contents can vary from 17 to 27% and 12 to 32%, respectively, among genetic variations (Dowd et al., 2010; Kohel et al., 1985; Yu et al., 2012). Elmore et al. (1979) found that N fertilization increased N levels in cottonseed with altered amino acid concentration. Pettigrew and Dowd (2011) reported that varying planting dates or irrigation regimes altered cottonseed composition in terms of protein, oil, gossypol, and soluble carbohydrates. Poultry litter (a mixture of manure and other external materials, such as bedding materials) is a byproduct of the poultry industry and contains valuable plant nutrients. Managed appropriately, land application of PL as a fertilizer is an effi cient and environmentally-acceptable method of recycling nutrients and organic matter. Long-term application (up to 20 yr) of PL into pasture soil continuously increased the hay yield in the Sand Mountain region of Alabama (He et al., 2008). Similarly, fertilizing cotton plant with PL oft en results in a yield increase (Endale et al., 2002; Reddy et al., 2007; Tewolde et al., 2009a). However, the information on the eff ect of PL application on mineral composition of plants is very limited even though PL contains many mineral elements (Schroder et al., 2011). Citak and Sonmez (2010) evaluated the eff ects of the types of fertilizers (farmyard manure, chicken manure, blood meal, and chemical fertilizer) on nutrient content of the edible part of cabbage (Brassica oleracea) plants during two consecutive seasons. Th ey found that the mineral contents of cabbage receiving organic applications tended to be higher than cabbage receiving chemical fertilizers, and on the whole, cabbage responded the best to farmyard and chicken manure as a mixture or separately.

The inability to incorporate manure into permanent pasture leads to the concentration of nutrients near the soil surface with the potential to be transported off site by runoff water. In this study, we used rainfall simulations to examine the effect of broiler chicken (Gallus gallus domesticus) litter application method and the runoff timing on nutrient and E. coli losses from tall fescue (Festuca arundinacea Schreb.) pasture on a Hartsells sandy loam soil (fine-loamy, siliceous, subactive, thermic Typic Hapludults)) in Crossville, AL. Treatments included two methods of litter application (surface broadcast and subsurface banding), commercial fertilizer, and control. Litter was applied at a rate of 8.97 Mg ha(-1). Treatments were assigned to 48 plots with four blocks (12 plots each) arranged in a randomized complete block design to include three replications in each block. Simulated rainfall was applied to treatments as follows: Day 1, block 1 (runoff 1); Day 8, block 2 (runoff 2); Day 15, block 3 (runoff 3); and Day 22, block 4 (runoff 4). Total phosphorus (TP), inorganic N, and Escherichia coli concentrations in runoff from broadcast litter application were all significantly greater than from subsurface litter banding. The TP losses from broadcast litter applications averaged 6.8 times greater than those from subsurface litter applications. About 81% of the runoff TP was in the form of dissolved reactive phosphorus (DRP) for both litter-application methods. The average losses of NO(3)-N and total suspended solids (TSS) from subsurface banding plots were 160 g ha(-1) and 22 kg ha(-1) compared to 445 g ha(-1) and 69 kg ha(-1) for the broadcast method, respectively. Increasing the time between litter application and the first runoff event helped decrease nutrient and E. coli losses from surface broadcast litter, but those losses generally remained significantly greater than controls and subsurface banded, regardless of runoff timing. This study shows that subsurface litter banding into perennial grassland can substantially reduce nutrient and pathogen losses in runoff compared to the traditional surface-broadcast practice.

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Significant quantities of the broiler chicken (Gallus gallus domesticus) litter produced in the USA are being applied to pasture lands. The traditional surface-broadcast application of animal manure onto permanent pasture, however, may lead to high concentration of nutrients and pathogenic microorganisms near the soil surface that could be transported off site by runoff water. Subsurface banding of poultry litter has the potential to reduce nutrient and pathogen losses through runoff. However, this has not been thoroughly investigated. In this study, we used rainfall simulations to examine the effect of broiler litter application methods on the longevity of nutrient and Escherichia coli losses in runoff by successive runoff events. Runoff plots were constructed on Hartsells fine sandy loam (Typic Hapludults) soil with permanent Kentucky 31 tall fescue (Festuca arundinacea) pasture in Crossville, AL. Treatments included two methods of litter application (surface broadcast and subsurface banding), commercial fertilizer, and control (no litter or fertilizer applied). To evaluate the longevity of nutrient losses, simulated rainfall (110 mm h −1 ) was applied to each plot on days 1, 7, and 14 following litter and fertilizer applications. Total P (TP), inorganic N, and E. coli concentrations were all significantly greater in runoff from broadcast litter application than the subsurface litter banding treatments. The TP losses from broadcast litter applications averaged 6.5 times those from subsurface litter applications. About 81% of the runoff TP concentration was in the form of dissolved reactive phosphorus for both litter application methods. The average losses of NO 3 -N and total suspended solids from subsurface litter banding plots were 358 g ha −1 and 68 kg ha −1 compared to 462 and 60 kg ha −1 for the broadcast method, respectively. This study shows that subsurface banding of broiler litter into perennial grassland can substantially reduce nutrient and pathogen losses in runoff compared to the traditional surface-broadcast practice.

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