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.

No abstract

No abstract

Whole cottonseed and its derived products can be used as human food, animal feed, and industrial raw material. Chemical composition of cottonseed is one of the critical parameters for evaluating its quality and potential end use. Especially, protein and dietary fibers are two desirable nutritional properties of cottonseed for animal feed. In this study, we determined their contents in cottonseed harvested from different fertilization managements with or without wheat cover crop in two consecutive years. Seed content of crude protein increased in the order of no fertilizer ≤ poultry litter ≤ chemical fertilizer. Both neutral and acid detergent fiber profiles were affected by fertilization and planting year/cover crop in an order reversing that of crude protein. Few statistically significant (P>0.05) impacts were observed on the content of acid detergent lignin. Observations derived from this work will provide information on nutritional value and digestibility of cottonseed as affected by cropping management practices.

Sweetpotato [Ipomoea batatas (L.) Lam.] storage root formation is a complex developmental process. Little quantitative information is available on storage root initiation in response to a wide range of soil moisture levels. This study aimed to quantify the effects of different levels of soil moisture on sweetpotato storage root initiation and to develop functional relationships for crop modeling. Five levels of soil moisture, 0.256, 0.216, 0.164, 0.107, and 0.058 m3·m−3 soil, were maintained using sensor-based soil moisture monitoring and semiautomated programmed irrigation. Two commercial sweetpotato cultivars, Beauregard and Evangeline, were grown in pots under greenhouse conditions and treatments were imposed from transplanting to 50 days. Identification of storage roots was based on anatomical, using cross-sections of adventitious roots, and visual features harvested at 5-day intervals from 14 to 50 days after transplanting (DAT). Recorded time-series storage root numbers exhibited sigmoidal responses at all soil moisture levels in both cultivars. Time to 50% storage root initiation and maximum storage root numbers were estimated from those curves. Rate of storage root development was determined as a reciprocal of time to 50% storage root formation data. Time to 50% storage root initiation declined quadratically from 0.05 to 0.15 m3·m−3 soil moisture and increased slightly at the higher soil moisture levels in both the cultivars. Cultivars differed in time to 50% storage root initiation and the storage root developmental rate. Soil moisture optima for storage root initiation were 0.168 and 0.199 m3·m−3 soil, equivalent to 63% and 75% field capacity for cultivars Beauregard and Evangeline, respectively. The data and the inferences derived from the functional algorithms developed in this study could be used to advise growers to schedule irrigation more precisely, make planting decisions based on available soil moisture, and to develop sweetpotato crop models for field applications.