Hp. Dossantos et al., CROP PRODUCTIVITY OF WHEAT ROTATION SYSTE MS FOR 10-YEAR PERIOD, IN PASSO-FUNDO, RS, BRAZIL, Pesquisa agropecuaria brasileira, 30(12), 1995, pp. 1397-1402
From 1980 to 1989, the effect of crop rotation systems for wheat was a
ssessed at the Centro Nacional de Pesquisa de Trigo (CNPT), in Passe F
undo County, RS, Brazil. Four rotation systems for wheat were studied:
system I (wheat/soybean); system II (wheat/soybean, rapeseed/soybean,
barley/soybean, and white lupine or serradella/corn); system III(whea
t/soybean, arrowleaf clover/arrowleaf clover, and arrowleaf clover/cor
n, from 1980 to 1983, and wheat/soybean, white oats/soybean, and commo
n vetch/corn, from 1984 to 1989); and system IV (wheat/soybean, rapese
ed/soybean, flax/soybean, and white lupine or serradella/corn). A rand
omized complete block design, with four replications and plots with 12
0 m(2), was used. Cultural productivity for that period, obtained by d
ividing grain yield (kg/ha) of each species by the energy consumed, is
presented in this paper. The energy consumed is the energy spent to p
roduce a good or a service. The global analysis showed no difference a
mong systems I (1.20 kg/Mcal), II (1.42 kg/Mcal), III (1.45 kg/Mcal),
and IV (1.40 kg/Mcal). In the annual average the alternative systems I
I, III and IV were five or more times higher than system I.