Jack has built small earthen dams in the furrows between the ridges on which he plants crops. Jack is using the method of water conservation. This method conserves water by holding precipitation water between the, allowing the water to infiltrate the soil and eliminate runoff.

o infiltrate the soil and eliminate runoff.

Rain water harvesting.

Explanation:

This a strategy of water conservation were the rainwater is harvested by the digging of ponds lakes and canals and then instating the rainwater catching ducts and then installing the filtration system in homes and putting a big tank under the ground surface so that rainwater is filtered and allows fir the water to get infiltrated in the soil and eliminate the runoff.