Cotton Links


Interest Leans To Increased Irrigation


Two important elements of managing water in a cotton operation involve adequate drainage and irrigation where it is physically possible and/or economically feasible.

In August, we asked our readers if, based on past weather, they would opt to improve drainage on their farms or increase irrigated acres. After tallying the votes, 62 percent say they will increase their irrigated acres, while 38 percent plan to improve drainage.

Most farmers, especially if they have been farming the same ground for a long time, have worked out any drainage issues they may have had. However, if a producer has picked up  additional land – whether bought or leased – he may have to do some drainage work for his water management program to work efficiently.

If drainage is already taken care of across the farm, then increasing irrigated acres may be the next step, which would explain the way the votes fell. For the 62 percent of the respondents who may increase their irrigated acres, Mississippi State University offers the following pointers about soil moisture, rainfall and irrigation.

“Most crops can utilize 2.5 to 3 feet of soil profile to extract moisture. This gives a growing plant 2.5 to 3.5 inches of available water to carry it without additional rainfall. Emerging crops use little moisture early in the season, and a good moisture profile will carry these plants for about a month without supplemental moisture.

“As the crops get larger and begin to canopy, a full profile will only last about eight to 14 days. This typically begins to occur in early June through August. Rainfall is the best hope for supplemental moisture since it is free, but it is not 100 percent effective. To determine how effective a rainfall is, use a soil probe, shovel or another device to see how deep the moisture soaked. As much as 75 percent of the water from a hard fast rain can run off, whereas a slow steady rain can soak in as much as 90 percent. The type of rainfall event determines its effectiveness as well as the amount of moisture already in the soil.

“Tillage will often dry out the soil surface as deep as two to three inches, but doesn’t really affect the deeper moisture. Rainfall is the best choice for replenishing the shallow moisture early in the year, but irrigation may be required during the summer months.

“Supplemental irrigation is not typically needed until mid- to late June on most crops under normal rainfall conditions. However, it is never too early to prepare for irrigation even if it is early because it will be needed in July and August to meet crop demand.”

Following is a sampling of the comments we received from people who voted in the August Web Poll.

• “I plan to add drainage to a couple of small places. Because of my age, I don’t consider irrigation. Either bankruptcy or retirement is in my future. If input costs don’t improve, I think bankruptcy will come first. This is from a north Alabama cotton farmer.”

• “From Westlands Water District, central California: Drainage is important ‘IF’ there is something to drain. Our prize Delta Smelt and whacky, radical environmentalists have made the decision very easy for us.”

• “Farm in West Texas; then you will not have to worry about drainage.”

• “You had better be able to get water off before you put water on !!!”

As the 2010 season approaches, talk on the turnrow indicates that U.S. cotton acreage will increase next year. In the October Web Poll, we are asking our readers where they think we will see the biggest increase in cotton acres. Cast your vote and, in the “Comments” section, explain why you chose a particular region.

To participate, go to www.cottonfarming.com. The results of the October poll will be reported in the Cotton Farming December issue.

Web Poll Results

In August, we asked: Based on weather conditions for the past two years, would you opt to improve drainage on your farm or try to increase irrigated acres? Please identify your area and explain your reasoning in the Web Poll “Comments” section.

• Improve drainage – 38 %
• Increase irrigated acres – 62 %

October Web Poll Question

Where do you think we will see the biggest increase in U.S. cotton acres in 2010 and why?

(1) Southeast
(2) Mid-South
(3) Southwest
(4) West

Register your vote at www.cottonfarming.com.

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