Effect ofRhizobium inoculation and nitrogen fertilization on alfalfa under irrigation

Abstract

Inoculation with Rhizobium meliloti and nitrogen fertilization on alfalfa increased the plant density, forage fresh yield and the protein content, and decreased the crude fibre content of alfalfa. Materials and methodsRhizobium meliloti strain ENRRI A12 was supplied by the National Centre for Research, Khartoum. Broth culture (400 ml of 1 × 10 9 cfu/ml) was aseptically added to 1kg of sterile fine charcoal adjusted to pH 6.7 and incubated in plastic bags at 26-28°C for 15 days. A series of pots were filled with Shambat clay soil with 17% silt, 31% sand and 48% clay; pH = 7.89, ECe = 1.10dS/m, SAR = 4.02; Na, Ca, Mg and K 5.83, 2.9, 1.3 and 0.26 mg/l, respectively, and N and P 0.04% and 0.011%, respectively. Ten seeds were sown in each pot and irrigated with tap water every 2 days. One week after sowing, urea was broadcast at the rate of 20, 40, 60, 80 and 100 kg N/ha and zero (control). The seedlings were thinned to six after emergence. Two weeks later the inoculum was injected around one triplicate set of seedlings at 5ml per plant, while another set was left uninoculated. Plants were harvested 10 weeks after transplanting.A field experiment was conducted at the University Farm in the semi-arid zone, with hot summers and a short rainy season in July-September with rainfall of 67.8 mm. Land prepared by deep ploughing, harrowing and levelling was ridged and divided into 5 × 3m plots. Seed at the rate of 50kg/ha coated with Rhizobium inoculum was broadcast randomly and irrigation water was applied immediately. Further irrigation was applied 5 days later and then every 11

Effect of Laser Irradiation and Rhizobium on Growth Parameters of Clover

“…Nitrogen, with or without Rhizobium, signi cantly increased the number of nodules per plant up to 80 kg N/ha. [ Elnesairy et al, 2005] The presence of a few weak nodules on the roots of uninoculated alfalfa plants indicates the presence of indigenous Rhizobium meliloti strains in Shambat soil, probably due to earlier inoculants applied in this area. The effect of Rhizobium in improving plant height, shoot fresh and dry weight, root fresh and dry weight, number of nodules per plant and plant density con rms earlier work such as Abuswar Mohamed (1997).…”

Nitrogen addition results inMedicago sativaswitching nitrogen sources

“…After growing 14 d in the greenhouse, liquid inoculum containing ~10 8 cell ml -1 of Sinorhizobium meliloti strain AFS32 was injected in the soil around the roots of the plants at a rate of 5 ml per plant to ensure nodule formation (Elkherbawy et al 1989;Elnesairy et al 2005). Two weeks after inoculation, the plants were fertilised with N at 7 the following rates: equivalent of annual rates of 0 (control), 2, 5, 10, 20, 50 g N m -2 yr -1 as NH4NO3, designated as N0, N2, N5, N10, N20 and N50, respectively.…”