Soils Under Conservation Agriculture with Vegetables in Siem Reap, Cambodia.

Smallholder vegetable farmers in Siem Reap, Cambodia experienced declining crop productivity. It could be a result of a mixture of factors such as nutrient and pest problems and extreme weather events such as droughts and heavy rains. The no-till, continuous mulch and diverse species principles of conservation agriculture (CA) could potentially increase vegetable yield by providing favorable microclimate and soil conditions for growth and development. CA is tested by fifteen women farmers in Cambodia in comparison to tillage. Areas planted to vegetables in this region are built up places to avoid water logging during rainy seasons. The soils come from the digging of reservoir for use during the dry seasons. Soil properties which are determined on site were found to be very acidic (pH=4.5) with low electronic conductivity (EC=0.03) and ranges from loamy sand to sandy clay loam texture. The acidity of the soil is a challenge as they do not apply lime. The application of lime on the farmer’s plots could improve the yield of vegetables. During the dry season Cambodia, higher soil moisture retention was observed with higher respiration rates under CA than in tilled. CA retains soil water for use by plants and reduces the soil temperature due to mulch. However, even with higher soil moisture retention, farmers still applies the same amount of water to CA plots than tilled. Farmers may start reducing their watering activity since CA due to mulch increases soil moisture retention. Two cropping seasons show vegetables are not affected by CA. Knowing CA could produce as much as tilled shows CA could be a promising technology for smallholder famers with the same agro climatic conditions.