Use of soil amendments in sustainable organic farming systems

Organic plant products offer numerous health benefits and it is essential to preserve soil productiveness without adding any synthetic chemical additives. Soil amendment materials particularly from organic sources are able to enhance the soil fertility for sustained environmental quality and plant productivity. Studies were conducted to investigate the effects of soil amendments (biochar and animal compost) on soil (cropped and non-cropped) properties (EC and pH), and on indicator plants (corn and cucumber) growth under organic farming system conditions. A greenhouse pot experiment was initiated in a randomized complete block design over the period of 8 weeks. The results showed that the cropped soil had significantly higher soil EC and lower pH compared to the non-cropped soil. The plant height, plant dry biomass and leaf chlorophyll content was also significantly higher in cropped soil compared to non-cropped. The biochar and compost amendments showed significant effects on soil EC, however they did not show any statistically significant differences for soil pH. Soil amended with compost exhibited a significant positive effect on plant height and leaf chlorophyll content, while biochar amended soil did not show significant effects on plant growth and chlorophyll content. Further studies on a range of soil properties are underway and will be discussed in detail. This study highlights the importance of studying the effects of organic amendments on soil properties and plant growth and comparing cropped and non-cropped soils.