Evaluation of Rhizobial Inoculation Methods for Chickpea

• Published in: Agronomy journal Vol. 94; no. 4; pp. 851 - 859
• Main Authors: Kyei‐Boahen, Stephen, Slinkard, Alfred E., Walley, Fran L.
• Format: Journal Article
• Language: English
• Published: Madison American Society of Agronomy 01.07.2002
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Cropping systems. Cultivation. Soil tillage; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Tending. Growth control; Tillage. Tending. Growth control; Canada; Saskatchewan; North America; America; Symbiosis; Symbionte; Seed treatment; Treatment efficiency; Cultivated soil; Plant nodule; Experimental study; Soil treatment; Grain legume; Leguminosae; Cicer arietinum; Placement; Dicotyledones; Bacterial inoculation; Angiospermae; Nitrogen fixation; Bacteria; Spermatophyta; Application method; Yield; Rhizobiaceae
• ISSN: 0002-1962; 1435-0645
• DOI: 10.2134/agronj2002.8510

Rhizobia inoculated onto legume seeds are often exposed to adverse environmental conditions, which can affect survival and subsequent effectiveness. Hence, soil‐applied granular inoculants have received much attention recently. We examined the efficacy of various inoculation methods at four sites in Saskatchewan, Canada, in 1997 and 1998 using desi‐ and kabuli‐type chickpea (Cicer arietinum L.). Seed inoculation treatments (liquid or peat‐based powder) were compared with soil inoculation (granular inoculant) either placed in the seed furrow or side‐banded (i.e., 2.5 cm to the side) at depths of either 2.5 or 8 cm below the seed. Nodule formation in the seed inoculation treatments was restricted to the crown region of the root system, whereas soil inoculation enhanced nodulation on the lateral roots. In 1997, granular inoculant placed below the seed increased kabuli seed yield by 36 and 14% over the liquid and peat‐based inoculants, respectively, whereas desi seed yield increased 17 and 5%, respectively. Seed yield responses were inconsistent in 1998. Seed protein concentration, percentage N derived from the atmosphere (%Ndfa), and amount of N2 fixed were typically lower for the liquid inoculant than for the peat and granular inoculants, which did not differ. The dry weight of lateral‐root nodules was highly correlated with yield parameters, suggesting that the lateral‐root nodules contributed significantly to N2 fixation and yield. Although the peat and granular inoculants were equally effective in establishing successful symbiosis, placing granular inoculant 2.5 to 8.0 cm below the seed may improve yield and quality.