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Biosolids as Nitrogen Source for Irrigated Maize and Rainfed Sorghum
Author(s) -
Binder Darren L.,
Dobermann Achim,
Sander Donald H.,
Cassman Kenneth G.
Publication year - 2002
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2002.5310
Subject(s) - biosolids , sorghum , agronomy , loam , fertilizer , environmental science , alfisol , sewage sludge , sewage , soil water , biology , environmental engineering , soil science
We quantified effects of anaerobically digested sewage sludge (biosolids) on yield, N use efficiency, and soil NO 3 over a period of 4 yr. Field experiments with five biosolids rates and six N rates were conducted at two sites on a silty clay loam soil: one with irrigated maize ( Zea mays L.) and another site with rainfed sorghum ( Sorghum bicolor L.). Biosolids rates for achieving maximum yields in the year of application were 62 Mg ha −1 (441 kg organic N ha −1 ) on irrigated maize and 36 Mg ha −1 (257 kg organic N ha −1 ) on rainfed sorghum. At those rates, the increase in relative yield (RY) was 33% in the year of application, 21% in the second year, 14% in the third year, and 9% in the fourth year. Approximately 40, 20, 10, and 5% of the total biosolids‐N was recovered by the crops in the first, second, third, and fourth year, respectively. In irrigated maize, use efficiency of biosolids‐N decreased with increasing biosolids rate, but was similar to that of fertilizer‐N. In rainfed sorghum, use efficiency of biosolids‐N was lower than that of fertilizer‐N. Little NO 3 accumulated in soil when biosolids were applied at the recommended rate, but application in excess of that required for maximum yield increased NO 3 accumulation in soil. The cumulative N fertilizer value of a biosolids application at the optimal rate was $136 ha −1 for maize and $68 ha −1 for sorghum. Biosolids had a total fertilizer‐N replacement value of $1.9 to 2.2 Mg −1 biosolids. Recommendations for biosolids use should be based on the total N input and its cumulative plant recovery and leaching potential across a 4‐yr period.