Articles
ECONOMIC EVALUATION OF COMPOST USE: SHORT-TERM RESULTS ON A MAIZE CROP
A maize crop was manured with: two rates of mineral fertilizers, three levels of municipal solid wastes plus sewage sludge compost, or two levels of a mixture of compost plus mineral fertilizers.
From the agronomical point of view, the basic difference between the two kinds of fertilization, observed for both soils, regards the yield function.
Curves describing yield responses to inorganic fertilizers didn’t provide a maximum, whereas those related to compost application showed a maximum in correspondence with about 254 and 223 t/ha/y of compost, for the two types of soil.
The corresponding corn grain yields were 9.2 and 10.5 t/ha respectively.
From the economical point of view, the maximum returns with mineral fertilizers were obtained distributing 200, 150, 300 kg/ha respectively of N, P205 and K20 on the first soil, and 170, 127 and 225 kg/ha on the other.
The corresponding yields were 9.3 t/ha and 10.1 t/ha with a profit of 609.00 $/ha and of 731.00 $/ha respectively.
Similar results could have been reached with a compost total cost of 1.6 $/t and 1.9 $/t.
The mere distribution cost is much higher, i.e. 3.00 $/t.
Therefore it was stated that, from the economical point of view, the use of compost is unfavorable if compared with mineral fertilization.