Symbiotic Efficiency of Native and Exotic Rhizobium Strains Nodulating Lentil (Lens culinaris Medik.) in Soils of Southern Ethiopia

Abstract

Lentil plays a major role in the food and nutritional security of low income Ethiopian families because of the high protein content of their seed; however, their productivity typically is low largely due to soil fertility limitations. Field and pot experiments were conducted during the 2011 cropping season to determine the effectiveness of Rhizobium strains on two cultivars of lentil in Southern Ethiopia. Six rhizobial inoculant treatments (four indigenous and two commercial inoculants), a nitrogen (N) fertilizer treatment (50 kg¨urea¨ha´1) and an absolute control (non-inoculated non-fertilized) were used. Inoculated plants produced significantly higher nodule number, nodule dry weight, grain yield and yield components than non-inoculated non-fertilized plants. Inoculation of field grown lentil with rhizobia strain Lt29 and Lt5 enhanced seed yield by 59% and 44%, respectively. Whereas urea fertilization enhanced yields by 40%. Similarly, grain yields were increased during the pot experiment by 92% and 67% over the control treatments by inoculation with Lt29 and Lt5, respectively. The highest levels of N fixation were achieved in plants inoculated with Lt29 (65.7% Ndfa). Both field and pot investigations indicate that inoculation of lentil with native rhizobial strains replace the need for inorganic N fertilization to optimize lentil yields.

Improvement of Faba Bean Yield Using Rhizobium/Agrobacterium Inoculant in Low-Fertility Sandy Soil

“…Our results showed that faba bean inoculation could effectively reduce the need of applied inorganic N-fertilizers while achieving higher grain yield. These findings are in line with those published by [36], who reported that, in a field experiment, inoculation of lentil by Rhizobium strains Lt29 increased seed yield by 59% while N fertilizer (50 kg urea ha −1 ) enhanced yields by 40% over the uninoculated non-fertilized control. Our results are also in agreement with another study [56] which indicated that inoculated soybean under field conditions produced higher or not significantly different seed yields and seed N-yield than the fertilized uninoculated control with 200 kg N·ha −1 .…”

“…Rhizobium-legume association can be manipulated, through inoculation under N-limiting field conditions, to improve crop production easily and inexpensively [35]. Where natural N 2 fixation is not optimal, inoculation is essential, ensuring that a high and effective rhizobial population is available in the rhizosphere of the plant [36]. The use of Rhizobium inoculants in legumes is the oldest agro-biotechnological application [37].…”

Effects of <i>Rhizobium</i> Inoculation and Phosphorus Fertilizer Rates on Growth, Yield and Yield Components of Chickpea (<i>Cicer arietinum L.</i>) at Goro, Bale Zone, Oromia Regional State

“…The increased shoot dry matter yield due to inoculation of chickpea with effective rhizobium strain (EAL0 29) could be the result of increased nitrogen fixation and its supply to chickpea, which enhanced crop growth. This result was similar with the finding of [12], who reported that inoculation of chickpea with CpSK strain increased shoot dry matter over the uninoculated control. However, there was no interaction effect of variety and phosphorus rate, variety and rhizobium inoculation and variety, phosphorus and different rhizobium inoculation on dry matter yield on chickpea.…”

Inoculation and N Fertilization Affect the Dry Matter, N Fixation, and Bioactive Compounds in Sulla Leaves

“…The important issue regarding the depressive effect on N fixation arising from the use of N rates in legume crops is still not duly considered. In fact, other reports based on the comparison of different inoculants or strains coupled with N applications in different legume species such as lentil, snap bean, and faba bean are available [34,51,52]. However, the same authors did not measure or consider that higher yields supported by N fertilization might reduce the N fixation efficiency of the same symbiosis.…”