INTEGRATION OF TIED RIDGES AND FERTILIZER USE TO ENHANCE WATER AND NITROGEN USE EFFICIENCIES FOR MAIZE PRODUCTION IN SEMI-ARID LANDS

Abstract

Low maize (Zea mays L.) production in arid and semi-arid lands (ASALs) has been attributed to inadequate soil moisture and declining soil fertility. This could be improved through enhanced water use efficiency (WUE) and nutrient use efficiency (NUE). During the short rain (SR) seasons of 2013 and 2014, a study was conducted at Kenya Agricultural and Livestock Research Organization (KALRO) – Katumani Research Station to monitor WUE, NUE and grain yield in maize production. A 2*2*4 factorial trial of cropping seasons, soil moisture conservation (tied versus untied ridging) and fertilizer types (control, CAN, FYM, CAN + FYM were set up in a Randomized Complete Block Design (RCBD). Rainfall data was put together for the entire study period. Soil and manure analysis were also done. Soil moisture content was monitored using a neutron probe moisture meter, CPN 503-DR. Analysis of variance was executed on soil moisture, maize grain yield and water and Agronomic Nitrogen Use Efficiencies using GENSTAT statistical software 14th edition. Treatments with significant differences were separated using Tukey’s at 95% confidence intervals. In both seasons, treatment combinations under untied ridges had higher soil moisture than those in tied ridging. Plots with tied ridges had higher WUE (1.87kg mm-1 ha-1 )

compared to those with untied ridges (1.00kg mm-1 ha-1 ). Tied ridge plus FYM plots

recorded the largest WUE in both SR 2013 (2.9 kg mm-1 ha-1

), SR 2014 (3.6 kg mm-1

ha-1 ) and in overall (3.23kg mm-1 ha-1 ). On average, maize yields were 53% higher in 2013 than in 2014 SR. FYM in tied ridges resulted in larger yields (294kg ha-1 )

compared to untied ridges (152kg ha-1

). Tied ridges (3.75kg grain-1 kg N-1 ) had higher

NUE than untied (-0.75kg grain-1 kg N-1 ). In both SR 2013 (6.6 kg Nha1

) and SR 2014

(3.6 kg Nha1

) seasons, plus the overall mean highest NUE was observed in FYM under tied ridge plots. Application of FYM in combination with CAN and tied ridges seemed to be the best bet for increased maize yields through enhancing both NUE and WUE.