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Description:
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Biosolids are a by -product of wastewater treatment with high organic matter content . The use of biosolids to improve arid rangelands has not been extensively studied . Biosolids rates of 0 , 14 , 36 , or 68 dry Mg /ha /yr were applied to tobosagrass (Hilaria mutica (Buckl . ) Benth . ) in a desert grassland in west Texas . Biosolids were applied twice -a -year either in winter /summer (WS ) or spring /summer (SS ) for one year only or two consecutive years . Half of the plots were irrigated . In the first growing season , tobosagrass plant length increased with WS appHcations , irrigation and at 36 and 68 Mg /ha application rates . Tobosagrass standing crop increased at the 68 Mg /ha rate in both seasons , with a more dramatic increase (86 % ) above control rates with WS applications . In the second growing season , tobosagrass length responded to all biosolids rates , WS applications for one year only , and irrigation . Tobosagrass standing crop responded with 26 , 51 or 41 % increases above the control at 14 , 36 or 68 Mg /ha , respectively . Standing crop increased in irrigated plots applied for one year only and for two consecutive years . Biosolids either did not affect or increased tobosagrass plant length and standing crop during the two years of this study . Application of biosolids to desert grasslands appears to offer a viable alternative for biosolids management and recycling . |