MATTIGA PANOMTARANICHAGUL1, MICHAEL FULLEN2, KARL STAHR3
1Chiang Mai University, Dept. of Plant Science and Natural Resources, Thailand
2University of Wolverhampton, School of Applied Sciences, United Kingdom
3University of Hohenheim, Department of Soil Science and Land Evaluation, Germany
The Shasea, Borassus and Uplands projects were conducted to find out the best technique for building a sustainable highland rainfed agriculture in northern Thailand during 2000-2009. The 1st-Shasea project focused on using the INCOPLAST, (Incorporated plastic and straw mulching technique), while the 2nd- Borassus and the 3rd-Uplands projects used biogeotextile or bio-degradable materials for surface mulching, to decrease soil erosion and increase water use efficiency. The studied cultural practices in the 3 projects were: conventional contour planting (CC or CP), contour ridge with and without plastic mulching (CR and CRP or INCOPLAST), alley cropping with hedgerows of mixed fruit tree varieties (AL), cultivated furrow (CF) and mulching (M) with imperata grass panel/ bamboo mat/ banana leave/ bamboo grass/vetiver grass (Im/B/Bn/Bg/Vg). The studied treatments in the 1st, 2nd and 3rd trials were CC, CR, CRP, AL, and CP, CP-BM, CF-BM, CF-AL, CF-BM-AL and CP, CP-Bn/Bg/VgM-AL, CF-AL, CF-Bn/Bg/VgM-AL respectively. The annual relay crop rotation were corn, upland rice and lablab bean.
The 1st trial-results showed that AL conserved most soil and water by reducing soil loss and runoff, while CRP or INCOPLAST induced higher runoff during the wet seasons but effectively reduced soil water evaporation during the dry period when compared to CC or CR. The 2nd experimental results showed that furrow cultivation mulched with imperata grass panel (CF-IM-AL) or bamboo mat in alley cropping (CF-BM-AL) gave the lowest soil loss and runoff, leading to the highest crop yields when compared to the other contour cultivations. However, bamboo mat and imperata grass panel were not practical due to high cost investment. The results of the 3rd trial indicated that contour furrow cultivation mulched with any biodegradable material (CF-Bn/Bg/Vg M-AL) gave the lowest amount of runoff and soil loss, leading to the highest crop yields, when compared to the other treatments. The above results indicated that the most practical technique for building a sustainable highland rainfed agriculture was the ``Integrated Water harvesting, Anti"=erosion, and Multiple cropping'' technique called ``IWAM''. It consisted of contour furrow cultivation with mulching and multiple cropping for increasing a permanent crop productivity and income flow for the farmer.
Keywords: Alley cropping, furrow cultivation, Biogeotextiles, INCOPLAST, IWAM