Pre-plant biocide uses of aqueous cyanamides

A method for using a pre-plant biocide to prepare a cultivation medium for growing a plant, the method comprising:

• i) irrigating an unplanted cultivation medium to a greater than 50% water saturation level;
• ii) after the irrigating, allowing the irrigated cultivation medium to drain to a saturation level of 50%-25%;
• and
• iii) contacting the cultivation medium with the pre-plant biocide comprising water and hydrogen cyanamide at a concentration of 600-10,000 ppm, thereby uniformly applying the pre-plant biocide, wherein the contacting is performed 30 to 90 days prior to a time of planting the plant;
• and wherein:
• (a) the applying the pre-plant biocide reduces a number of viable pathogenic nematodes in the root zone of the cultivation medium by at least about 90% to a depth of 4 feet at the time of planting relative to an untreated control cultivation medium;
• (b) the applying the pre-plant biocide reduces a number of viable weeds in the cultivation medium by at least about 99% at the time of planting relative to an untreated control cultivation medium;
• or
• (c) the applying the pre-plant biocide reduces a number of viable pathogenic fungal organisms in the cultivation medium by at least about 90% at the time of planting relative to an untreated control cultivation medium.