Cj. Pilbeam et al., Productivity and economic benefits of integrated nutrient management in three major cropping systems in the mid-hills of Nepal, MT RES DEV, 19(4), 1999, pp. 333-344
Combined applications of manure and inorganic fertilizer (integrated nutrie
nt management) may allow sustainable cropping with higher productivity and
larger economic benefits than applications of either one alone. This is bei
ng examined in three of the major crop rotations in the mid-hills of Nepal.
These are rice-wheat on irrigated khet land, millet, either relayed or gro
wn sequentially after maize, on rain-fed bari land, and blackgram grown aft
er upland rice on ancient river terraces, tar land. At each of the six site
s seven different nutrient treatments were applied either to a single crop
(maize and upland rice) or to both crops (rice and wheat) in the rotation.
Manure or inorganic fertilizer, or equal parts of both, were applied at a h
igh rate and at half that rate. A treatment with no additions was also incl
uded. Crops of millet and blackgram were unfertilized.
Grain yields of maize, upland rice, wheat, and rice were greater at the hig
her rate of N, as were straw yields. Grain and straw yields were greatest f
ollowing application of fertilizer alone, except for maize at Pakhribas and
wheat at Kholitar, and rice grain yields at Kholitar. For most crops, labo
r costs exceeded the market value of the yields from the zero-input treatme
nt. Partial budget analysis showed that margins were generally negative whe
n manure was applied either alone or in combination with fertilizer, but po
sitive with applications of fertilizer. Results imply that applications of
fertilizer are advantageous in the short-term.