Method and composition for agricultural potassium fertigation

1. A method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field, said agricultural field being irrigated by means of an active emitter-irrigation system having a stream of flowing irrigation water upstream of said agricultural field, said method comprising the steps of:

(step 1) converting said irrigation water to treated irrigation water by continuously charging a potassium-nutrient feedstock to said stream of said flowing irrigation water upstream of said agricultural field whereby said irrigation water is converted to treated irrigation water,

wherein said potassium-nutrient feedstock is comprised of comprises potassium formate and water;

(step 2) irrigating said agricultural field with said treated irrigation water; and

(step 3) repeating step 1 and step 2 each irrigation day over a prolonged term.

2. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 14, wherein said potassium-nutrient feedstock is comprises a 50 to 75 wt. percent aqueous solution of potassium formate.

3. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 , wherein said potassium-nutrient feedstock is a 65 50 to 75 wt. percent aqueous solution of potassium formate.

4. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 , wherein said emitter-irrigation irrigation system is a comprises said micro-irrigation system.

5. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 , wherein said emitter-irrigation irrigation system is comprises an overhead sprinkler system.

6. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 wherein, in step 3, said prolonged term is from 50 to 100 percent of said crop cycle.

7. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 14, wherein, in step 3, said prolonged term potassium-nutrient feedstock is from continuously or substantially continuously charged to said stream of irrigation water during 75 to 100 percent of said crop cycle.

8. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 7, wherein, in step 3, said prolonged term potassium-nutrient feedstock is from continuously or substantially continuously charged to said stream of irrigation water during 90 to 100 percent of said crop cycle.

9. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 14, wherein, in step 3, said prolonged term potassium-nutrient feedstock is continuously or substantially continuously charged to said stream of irrigation water in a three month time period during said crop cycle.

10. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 wherein, in step 3, said prolonged term is a five month time period during said crop cycle.

11. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 14, wherein, in step 1, said continuously charging of said potassium-nutrient feedstock provides a concentration of from 1 to 200 ppm of potassium as K2O K 2 O in said treated irrigation water.

12. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 wherein, in step 1, said continuously charging of said potassium-nutrient feedstock provides a concentration of from 5 to 100 ppm of potassium as K2O K 2 O in said treated irrigation water.

13. The method of prolonged-termed emitter-irrigation potassium fertigation of an agricultural field according to claim 1 wherein said active agricultural emitter-irrigation system includes a main line and a side-arm mixing chamber off said main line, and said stream of flowing irrigation water is flowing flows through said side-arm mixing chamber and discharging discharges to said main line, and

wherein, in step 1, said continuously charging of said potassium-nutrient feedstock to said stream of said flowing irrigation water upstream of said agricultural field is a comprises continuously charging of said potassium-nutrient feedstock to side-arm mixing chamber.

14. A method of potassium fertigation of an agricultural field, said agricultural field being irrigated using an irrigation system having a stream of irrigation water upstream of said agricultural field, said method comprising:

charging a potassium-nutrient feedstock to said stream of said irrigation water upstream of said agricultural field to convert said irrigation water to treated irrigation water, wherein said potassium-nutrient feedstock includes potassium formate and water; and

irrigating said agricultural field with said treated irrigation water,

wherein, during at least 50% of a growing season or crop cycle, said potassium-nutrient feedstock is continuously or substantially continuously charged to said stream of irrigation water upstream of said agricultural field, and said agricultural field is irrigated with said treated irrigation water in multiple consecutive irrigations.

15. The method of claim 11, wherein said concentration is from 5 to 100 ppm of potassium as K 2 O.

16. The method of claim 14, wherein said irrigation system comprises an emitter-irrigation system, a micro-irrigation system, or an overhead sprinkler system.

17. The method of claim 14, wherein said potassium-nutrient feedstock includes 28-42% of potassium as K 2 O, and does not include sulfate, thiosulfate, phosphate or chloride.