Comparisons of farmyard manure, sewage sludge, and other organic manures tested on potatoes and a succeeding cereal crop at Rothamsted

Abstract

Modern field experiments on the manorial values of sewage sludges began in the 1930's when Cranfield (1939) tested local sludges at centres in the Midlands, and Rothamsted Experimental Station (1938) had a factorial series of trials testing fermented town refuse and its interactions with fertilizer nutrients. This work was greatly stimulated by the wartime shortage of fertilizers and an elaborate series of field experiments was initiated at Rothamsted in 1940.Various types of sewage sludge, straw composts and town refuses were tested, and their interactions with fertilizers were examined on a range of crops andsoils. A brief report on this work, with a summary of the results then available, was made for the Ministry of Agriculture (Agricultural Research Council, 1948) and the detailed results of 100 of the full-scale experiments done on commercial farms has been published (Bunting, 1963). A simplified series testing similar organic materials on microplots, chiefly at rural schools, has also been reported (Garner, 1962). The parent experiment at Rothamsted was larger and lasted longer than any of the others; it also contained features, such as the inclusion of different farmyard manures made under standard conditions, and the assessment of residual effects, that could not be repeated elsewhere. This paper records some of the agricultural results of this experiment. EXPERIMENTAL Description of the experiments and the manures testedThe experiments were done yearly on different fields from 1940 to 1949 at Rothamsted on heavy loam that had carried a long sequence of arable crops. The manures were applied to potatoes in the first year, and the succeeding cereal crop measured residual effects. The chief organic manures tested were: 8 kinds of farmyard manure (FYM) made under controlled conditions, sewage sludge from 7 sources, sludge-straw composts from 4 sources, 5 types of town refuse, cut bracken stacked over winter, and peat.A 5 x 5 lattice square design tested 11 materials each at single and double rates, and 3 controls without organic manure. These 25 main plots were repeated in 3 blocks and each was divided into 4 subplots to test fertilizer N, P and K in all combinations, confounding the 3-factor interaction. There were therefore 300 subplots in each experiment. The rates of dressing at the single level were: (a) Farmyard manure: 8 tons per acre for fresh material made with 8 lb. of litter per beast per day; the other manures were applied in amounts corresponding to the quantity of feeding stuffs used to make the 8 tons of fresh FYM. Details of making the experimental manures are given later.(6) Sewage sludges supplying 5 tons of dry matter per acre.(c) Town refuses, sludge-straw composts, and rotted bracken at 8 tons/acre.(d) Peat at 2 tons/acre. The fertilizers tested supplied: 0-6 cwt. N per acre as ammonium sulphate; 0-6 cwt. P 2 O 6 per acre as superphosphate; 1-0 cwt. K 2 O per acre as muriate of potash. In 1940 and 1947 phosphate was not tested, but a basal dressing of superphosphate supplying 0-6 cwt. ...

Value of Manure and Sewage Sludge as N Fertilizer1

“…Many researchers have found manure to be a source of N (6,9,11,12). Soluble urine-N produced similar yields to those obtained with inorganic N fertilizers, whereas total N in animal manures ranged from about 20 to 50% as effective as commercial fertilizer N in short term experiments ( 1 ).…”

“…Some workers have demonstrated that either the digested or activated sludges are N sources for plant growth (3,4,7,8,9). Bunting (6) concluded that dry sewage sludge was a source of N and P, but very deficient in K, whereas Coker (7) found that liquid sludge gave similar yields as an equivalent amount of N applied as NH4NOa.…”