Abstract: A field experiment was conducted in Lijiabu Town of Dingxi City, Gansu
 Province to study the soil respiration and its relations with the canopy temper
ature and soil moisture content in a rotation system with spring wheat and pea u
nder effects of different tillage measures. Six treatments were installed, i.e.,
 tillage with no straw- or plastic mulch (conventional tillage, T), tillage wit
h straw mulch (TS), tillage with plastic mulch (TP), no-tillage (NT), no-tilla
ge with straw mulch (NTS), and no-tillage with plastic mulch (NTP). During the
growth periods of spring wheat and pea, soil respiration had different change pa
tterns, with the peaks appeared at the early jointing, grain-filling, and matur
ing stages of spring wheat, and at the 5-leaf, silking, flowering and poding, a
nd maturing stages of pea. There was an obvious difference in the diurnal change
 of soil respiration in spring wheat field between treatments NTS and T, and the
 soil respiration rate was significantly lower in NTS than in T; while the soil
respiration in pea field had less diurnal change. Soil respiration rate had a si
gnificant linear relationship with the canopy temperature of both spring wheat a
nd pea, the correlation coefficient being the highest at booting stage of spring
 wheat and at flowering and poding stage of pea, followed by at grain-filling s
tage of spring wheat and at branching stage of pea. There was also a significant
 parabola relationship between soil respiration rate and soil moisture content,
the correlation coefficient being higher under conservation tillage than under c
onventional tillage, with the highest under NTS. The moisture content in 10〖KG-*2〗-〖KG-*7〗30 cm soil layer of spring wheat field and that in 5〖KG-*2〗-〖KG-*7〗10 cm soil layer of pea field h
ad the greatest effects on soil respiration. Comparing with conventional tillage
, all the five conservation tillage measures decreased soil respiration, with th
e best effects of no-tillage with straw mulch.

Key words: tillage measure, farmland, soil respiration, spring wheat, pea, mixed broadleaved-Korean pine forest, seedling composition, topography, mortality, recruitment.