Water use and grain yield response of rainfed soybean to tillage-mulch practices in southeastern Nigeria

Abstract

Despite the agronomic, economic and food values of soybean (Glycine max L. Merrill), there is still dearth of information on the tillage need and the implications of surface mulch for the crop in the eastern part of the forest-savanna transition zone of Nigeria. This study was therefore carried out on a sandy loam Ultisol at Nsukka with a sub-humid climate, during 2006 and 2007 cropping seasons. Our objective was to devise an appropriate tillage method for the crop from evaluated effects of no-till (NT), conventional tillage (CT) and mulch on selected key agronomic indices. Each of the NT and the CT was either unmulched (U) or mulched (M) in a split-plot, giving four treatments/tillage methods (NTU, NTM, CTU and CTM) randomized in four blocks. Rainfall was more favorable in the first than in the second season. The mean seasonal soil water storage (range, 99-109 mm) within 0.5-m soil layer differed among the treatments (NTU < CTU < NTM = CTM). However, for the first and second seasons, both water use (582-616 and 667-709 mm respectively) and grain yield (0.71-0.81 and 1.22-1.91 Mg ha -1 respectively) were not different. Mulch lowered the crop water use but had no influence on grain yield. Water use efficiency was enhanced with mulch only in the second season. Although either of the two mulch treatments (NTM/CTM) would be suitable for growing soybean especially in years of unfavorably distributed rainfall, NTM is a more rational choice than CTM. Rainfall adequacy at the critical reproductive stage of the crop showed to be a more important yield factor than the tested tillage methods.

Cover Crops and Returning Residue Impact on Soil Organic Carbon, Bulk Density, Penetration Resistance, Water Retention, Infiltration, and Soybean Yield

“…Data from the present study showed that RR treatment had higher SWS compared to RNR treatments in 0-5 cm depth. Results corroborating these findings were observed in a study where the addition of mulch in no-till soybean cropping system increased mean seasonal soil water storage by 55 and 59 mm in years 2006 and 2007 respectively, compared to no mulch added (Obalum et al, 2011). Data from the present study showed that, in general, CC treatment has higher SWS compared with NCC treatments.…”

Agronomic evaluation of seedbed and mulching alternatives with plant spacing for dry‐season fluted pumpkin in coarse‐textured tropical soil

“…In the present location at Nsukka, for instance, surface mulch was found to increase the yield of soybean ( Glycine max M.) that provided cover to the soil, and this was even under rainfed conditions (Obalum et al. ). There have been similar reports of mulch‐induced increases in fresh and dry weights of vegetables including fluted pumpkin (Okugie and Ossom ; Mahadeen ; Aniekwe ).…”

Expounding the Value of Grain Legumes in the Semi- and Arid Tropics

“…To date, there has been separate attempts by crop scientists [16][17][18][19][20][21][22] and nutritionists [11][12][13] to address the knowledge gap on legumes. These efforts have been disciplinary and the information is yet to be consolidated so as to make meaningful impact on policy.…”