The Effects of Potassium Chloride to Counteract the Negative Effects of Side-banded Urea on Plant Establishment
A series of experiments to determine if adding KCl to side-banded urea would increase the safety to the seedlings against the toxic effects of side banded urea, regardless of the separation between the seed and fertilizer. No significant effect was observed, although there was one site-year observed where addition of KCL with urea in the side-banded urea for flax was beneficial.
IPNI-1999-CAN-SK22
02 Mar 2000
1999 Annual Interpretive Summary
The Effect of Potassium Chloride to Counteract the Negative Effects of Urea Side-Banded on Plant Establishment Using Different Placement Configurations and Soil Types, 1999
The application of KCl fertilizer in bands with urea has been suggested as an effective means of reducing urea toxicity from the accumulation of both NH3 and nitrite (NO2) in the soil. Accumulations of free NH3 can be very toxic to the roots of newly developing seedlings. Creating an acidic (low pH) environment in the vicinity of a urea band will temporarily reduce the process of urea hydrolysis, allowing seedling germination in the absence of free NH3. With the rapid expansion of no-till seeding systems in western Canada, many farmers are now applying all of their urea fertilizer in a side band close to the seedrow at seeding. There are several reports from research trials that even when side-banded away from the seed, stand reductions occur with the application of high rates of urea. This new two-year project was established to evaluate the impact of urea side-banded with KCl on the establishment of spring wheat and flax seedlings in no-till production systems.
Results from the first year of this study show that increasing side-banded urea N rates resulted in a significant reduction in flax establishment, while the impact on wheat was minor. Increasing the urea band separation from 1 inch side x 1.5 inch below to 1 inch side x 3 inch below reduced the negative effects on the flax. While the addition of KCl to the urea bands did not reduce the negative effect on flax or wheat seedling establishment, it did improve flax grain yield by 19 percent at a sandy loam trial location. A review of soil samples from the location revealed that while K levels were high, Cl levels were well below the sufficiency range. A second year of data collection is planned for 2000. SK-22F