MIXED CROPPING SYSTEMS

Abstract

Kandyan forest gardens are typical examples of perennial mixed cropping systems in SriLanka. However due to the nonsystematic cropping of these units the Delpitiya MixedCropping Model (DELMIX) was developed and planted in 1978 on eroded tea land. Yielddata of DELMIX indicate that yields of all the crops increased with the time. Cost versusincome of DELMIX confirmed that it is profitable. Therefore DELMIX has proved to beeconomically viable. Evaluation of submodels selected from DELMIX indicate that plantheight and canopy width of crops were similar in all submodels but varied in crop yields.Some of the farmers adopted part of the model very satisfactorily,which shows the farmershave an interest on the submodels of DELMIX.

A modified DELMIX pepper and coffee (catimor) model at different spacings with Acaciamangium as a wind belt was planted in 1986 at Nillambe. Yield data of these modelsindicate that the maximum yield per plant and maximum yield per unit area (kg/ha) ofboth coffee and pepper was obtained in the model of coffee in 1.5m x 3m and pepper in 3 x3m.

In the DELMIX no paticular soil conservation measures were adopted. Moreover, thestope of land used for OELMIX was not excessive. Currently available lands for mixedcropping has a steeper slope than that at the DELMIX site. Therefore studies on mixedcropping with the less costly conservation method of Sloping Agricultural LandTechnology (SALT) is in progress at Delptitya with good results.