Optimizing Phosphorus Fertilization and Inoculation in Chickpea and Lentil

Saskatchewan is the world’s largest exporter of lentils and has the fastest expanding acreage of chickpeas. These two drought-tolerant pulse crops have been integrated into the farming systems in the semi-arid regions of western Canada as a means of diversifying crop production and improving whole-farm economics. In order to expand our knowledge with these new crops, a project was initiated at two locations in the semi-arid region of Saskatchewan, evaluating the effect of fertilizer phosphorus (P) on crop development and grain yields for desi and kabuli chickpea and lentil grown on soils with a medium level of soil residual P.

This field study is being conducted to determine the impact of starter P (15 lb P₂O₅/A) on growth, yield, and seed size in chickpea. Preliminary data from the five site-years (1999, 2000, and 2001 at Swift Current and 2000 and 2001 at Stewart Valley) of the study showed that starter P, as compared to a zero-P treatment, did not affect plant establishment, maturity, or seed yield of either Desi or Kabuli chickpeas. However, the starter P increased the lowest pod height of Kabuli-chickpea by 0.6 inches, implying an improvement of harvest ability of 6 percent. When Kabuli chickpea was seeded in mid to late May and P applied at the highest rate (30 lb P₂O₅/A), an increase in the proportion of the 9-mm (0.35 in.) diameter seeds (54 percent vs 59 percent) triggered an increase of the price premiums that would be paid for the large seed. However, this response was not observed when the crop was seeded in early May. The earlier-seeded chickpea may have developed a larger root system, increasing the uptake of nutrients from the soil and reducing the response to added fertilizer P. SK-25F