EFFECTS OF POTASSIUM CHLORIDE AND INTER ROW SPACING ON YIELD AND YIELD COMPONENTS OF MAIZE (Zea mays L) IN SOFI DISTRICT, EASTERN ETHIOPIA

Abstract

Maize is one of an important cereal crop in Ethiopia due to its uses as sources of food and income generation. Its productivity is constrained by drought, blanket fertilizer recommendation and non-optimum plant population. The experiment arranged in a factorial combination in a randomized complete block design (RCBD) by replicating three times. It contain Four Potassium Chloride (KCl)(0 kghe-1, 20 kghe-1, 40 kghe-1 and 60kghe-1 )levels and four level of inter row spacing (IRS)55 cm, 65cm, 75, cm and 85cm. The objective of the study is to investigate the optimum rate of KCl and plant population for Maize yield and yield component and to investigate cost benefit analysis of KCl fertilizer rates on maize yield. The findings of the study revealed that the interaction effect of two factors IRS and KCl rate were highly significant (p<0.01) on data such as number of ear per hector (NEha-1), grain yield (GY), number of row per ear (NRE-1), number of grain per row (NGR-1), number of grain per ear (NGE-1) and above ground dry bio mass (AGBM). Number of ear per hector (NEP-1), harvesting index (HI) and thousand grains weight (TGW kg) data were significantly (p<0.05) affected by interaction effect of KCl and IRS. The main effects of KCl levels was highly significant (p<0.01) on parameter such as day to 90% physiological maturity (DPM 90%), day to 50% silkin (DS 50%) and agronomic efficiency (AGE), While leaf area (LA) was significantly (p<0.05) affected by KCl rate. The main effect of IRS was highly significant (p<0.01) on data such as: Day to 90%Physiological maturity, Day to50%anthesis, plant height, stand count present, ear length, ear diameter and agronomic efficiency. While Day to 50% Silking, leaf area and leaf aria index ware significantly (p<0.05) influenced by the Main effect of IRS. The highest yield (4662kgha-1) recorded from the highest level of KCl (60 kg he-1 ) interacting with 75cm IRS. The lowest yield (2853 kgha-1) recorded from 0kgha-1 KCl and narrowest IRS (55 cm). The highest net benefit 158097.7 Birr he-1 recorded from the combination of 40 kghe-1 of KCl level with 75 cm inter-row spacing with MRR 69848.85% and lowest net benefit 80159.2 Birrhe-1 from 0kghe-1 KCl and narrowest IRS (55 cm).The currently using practice (75 cm IRS without KCl), gave an economic return of 127634.1Birr ha-1 with MRR of 729.04%. The application of 40 kg KClhe-1 with 75 cm IRS resulted in 23.9 % increment to the income from that of the currently used practice. The researcher conclude that use of 40kg KClhe-1 combining with 75 cm inter row spacing is optimum for maize crop production at the study area and the area within similar agro-ecology. However, sound recommendation cannot draw from this study since the research conducted only for one cropping season in a single location. Therefore, the researcher suggests that further KCl levels with IRS studies have to be conducted for more than one season with multi-locations in similar agro-ecology.