Integrating Scientific and Farmers' Evaluation of Water Harvesting and Soil Fertility Technologies on Sorghum Productivity in Eastern Kenya

Abstract

Soil fertility degradation remains the major biophysical cause of declining per capita crop production on smallholder farms in Kenya highlands. A study was conducted to compare farmers' perception and biophysical data on selected water harvesting and integrated soil fertility management technologies on sorghum (Sorghum bicolor (L.) Moench) and cowpea (Vigna unguiculata L.) production in Central highlands of Kenya. The treatments were 3 levels of water harvesting (Tied ridges, contour furrows and conventional tillage) 3 cropping systems (Sole sorghum and Sorghum and cowpea intercrop and 6 levels of soil fertility amendment options (control, 40 Kg P/ha + 40Kg N/ha, 40 Kg P/ha + 20 Kg N/ha, 40 Kg P/ha + 40Kg N/ha + manure 5 t/ha, 40 Kg P/ha + 20 Kg N/ha + manure 2.5 t/ha and manure 5t/ha. One hundred seventeen smallholder farmers were invited to evaluate crops based on their performance and grain yields. Thirty six plots laid out in partially balanced incomplete block design (PBIDD) replicated three times. The results show that treatments that ranked top on the scale of 'good' had external soil amendment regardless of water harvesting and cropping systems. The treatment which was ranked best was farmers practice under sorghum alone plus external soil amendment of 40 kg P/ha + 20 kg N/ha with (69.1 %) respondent with grain yield of (3.5t/ha). This was closely followed by tied ridges and contour furrows rankings ranging from 68.3% to 68.8% respondent under sorghum alone, plus external soil fertility amendment options. Generally, the poorest ranked treatment and low yielding were experiment control. The results further showed that there was no significant difference between treatment scoring by gender (P~.05) on the scale of good, fair and poor. Therefore, integration minimal addition of organic and inorganic inputs on highly valued traditional with adequate rainfall under normal farmers practice in semi-arid lands could be considered as an alternative option contribution to food security in central highland of Kenya