Premium
Value of Manure and Sewage Sludge as N Fertilizer 1
Author(s) -
PomaresGarcia F.,
Pratt P. F.
Publication year - 1978
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1978.00021962007000060041x
Subject(s) - manure , agronomy , hordeum vulgare , sewage sludge , mineralization (soil science) , tonne , sorghum , forage , fertilizer , zoology , environmental science , chemistry , sewage , nitrogen , poaceae , biology , environmental engineering , organic chemistry
A greenhouse pot experiment in a Hanford soil (Typic Xerorthent) with rates of feedlot manure at 0, 20, 40, and 60 metric tons/ha and sewage sludge at rates of 0, 10, 20, and 30 metric tons/ha combined factorially with 0, 50, 100, 150, and 200 mg N/kg of soil as (NH 4 ) 2 SO 4 was conducted using barley ( Hordeum vulgare L.) and sudangrass ( Sorghum sudanense (Piper) Stapf.) as test crops. The objectives were to measure the net mineralization of N in the organic materials, to compare the availability of N in the organic materials with the N in (NH 4 ) 2 SO 4 and to determine the critical levels for N and NO 3 in barley. The available N from the organic materials was estimated from the amounts required to equal the N in (NH 4 ) 2 SO 4 in terms of barley forage production. Net mineralization was determined by soil analyses. Yields of barley forage were increased by additions of organic materials and (NH 4 ) 2 SO 4 . The addition of either manure or sludge decreased the response to (NH 4 ) 2 SO 4 . In a 2.5‐month period after application, the manure gave an average of 0.65 kg of available N/ton, whereas the sludge gave 7.05 kg of available N/ton. This represents 4.2% of the total N from the manure and 17.0% of the total N in the sludge. In a 10‐month period only 17.2 and 40.9% of the N in manure and sludge, respectively, had mineralized. The estimated critical levels of total N and NO 3 − ‐N in barley forage were 2.0 and 0.12%, respectively. These values were independent of the N source. The minimum content of total N in barley forage at which NO 3 − ‐N began to increase was about 2.0%. The level of NO 3 − ‐N in plant tissue was more sensitive than total N to changes in N supply.