Search Trials


Potassium applications improve fruit quality

Circumstances in which foliar applications are beneficial.

N and K deficiency imbalances can occur when the nutrient uptake from the soil solution via the root system is limited. For example:

• When K fertilizer applications to the soil are reduced
• In soils with low K reserves
• Due to cation antagonism
• After flowering, when nutrient uptake is slowed down, because of the reduced activity and decline of the root system
• When plant demand exceeds nutrient uptake

Under these growth-limiting conditions, foliar applications with Ultrasol® K or Speedfol™ NPK, based on potassium nitrate, may offer an alternative to soil applications in view of maintaining and/or restoring nutrient balances in the various plant tissues. This optimizes plant performance in terms of yield and/or quality, which in turn generates a maximum financial income for the grower.

Potential benefits of foliar Ultrasol® K in soybean.

Foliar applications with Ultrasol® K to provide N and K to soybean can have the following benefits:

• The ability to provide N and K when root activity is impaired, for example in saline or dry conditions
• Increased production and translocation of carbohydrates from the leaf to the pods and seeds
• Delayed leaf senescence at the end of growth, as longevity of leaves directly positively influences yield of soybean
• Supply of essential plant macronutrients, when plant demand exceeds nutrient uptake capacity via the roots

Main soybean growing countries and commercial potential
Figure 1. Main soybean growing countries and commercial potential. With 97 million ha, soybean is the fourth ranked crop grown worldwide after wheat, corn and rice. Major growing areas are in Latin America, North America and Asia. Each % of the total soybean growing area that would be sprayed with 4-10 kg Ultrasol® K per ha, reflects a potential sales volume of about 4-10.000 MT Ultrasol® K per year.

Soybean Growers Benefit from Ultrasol® K.

Potassium accumulation in different soybean plant parts.

From full bloom (growth stage R2) onwards, there is a steep increase in potassium uptake which lasts for about 60 days, until seed development is completed (R6). From the beginning of seed development (R5) onwards, potassium is remobilized from the other plant organs to the seed. At harvest, about 50% of total accumulated K is stored in the seed and another 15% of total accumulated K in the pod. Therefore, any K deficiency during pod and seed development will result in yield reduction.

Summary trial results with foliar applied Ultrasol® K solutions on soybean.

Scientific trials, carried out in Brazil and Argentina (Fig. 2), resulted in statistically significantly higher yields (+12% to +28%), with a single foliar application of 4 to 10 kg Ultrasol® K per ha in solution, applied onto the crop at R2-R3 (full bloom – beginning pod development) or R 5.4 (50% to 75% of the seed development completed) growth stages.

Figure 2. Ultrasol® K proves to be an ideal Specialty Plant Nutrition product because it comprises both nitrate and potassium, the two nutrient salts required in greatest amounts by the majority of plants and by just about every crop grown.