CA improved the saturated hydraulic conductivity of the top soil and the xylem sap flow of the rice
plant. CA resulted in higher grain yields at sites with low P availability and improved the response to N
and NP chemical fertilizer treatments. However, CA reduced leaf SPAD values, possibly through a
reduction of the availability of soil nitrogen, indicating that CA without additional N fertilizer application
could reduce grain yields in soils with a low indigenous N supply. These results suggest that CA has the
potential to improve soil productivity of upland rice production in Laos, but that the effect of CA
application is highly dependent on soil fertility and fertilizer management