Spring-like temperatures in late February and early March, coupled with below-normal rainfall, are just some of the challenges producers are facing as they prepare their fields for the 2009 growing season. However, there is one bit of good news: current soil moisture conditions are better than they were in 2008 within the 15-county High Plains Underground Water Conservation District No. 1 service area.
Those are the findings from the joint annual pre-plant soil moisture survey conducted by the High Plains Water District and the USDA-Natural Resources Conservation Service.
"Many areas of the Water District service area received above-average rainfall in 2008. Some significant rainfall amounts were received after crops matured in the fall. Because of this, most of the rain was not used by the plants and is available as deep moisture this season," said Gerald Crenwelge, USDA-NRCS soil scientist.
Annual pre-plant soil moisture survey data were collected by Water District and USDA-NRCS personnel from Jan. 19 to Feb. 9, 2009.
The overall average 2009 pre-plant soil moisture deficit was 2.15 inches in the upper three feet of the soil and 3.38 inches in the upper five feet of the soil. This is the amount of water needed, either by irrigation or rainfall, to bring these respective portions of the soil profile to field capacity prior to planting.
In comparison, the average pre-plant soil moisture deficit was 2.54 inches in the upper three feet and 3.62 inches in the upper five feet at the start of the 2008 crop year. That's a difference of 0.39 of an inch and 0.24 of an inch, respectively.
A total of 198 permanently-installed soil moisture monitoring sites were read this year. Each site is representative of the crops and farming practices in the area in which they are located. Moisture meters were used to gather readings for each six-inch interval in the upper five feet of soil.
Results of the 2009 survey are shown in soil moisture availability and deficit maps published in the March issue of The Cross Section, the district's monthly newsletter. The maps are also available for online viewing at http://www.hpwd.com/news/cross_section.asp. Printed copies of the newsletter are also available by contacting the High Plains Water District headquarters in Lubbock.
Since many areas within the High Plains Water District have had little or no rainfall in 2009, producers are encouraged to conserve existing soil moisture whenever possible.
"As we begin the year with little precipitation, it is very important to conserve the moisture currently present in the soil. Reducing the number of tillage operations will generally help conserve soil moisture. Shallow depth tillage practices that do not turn moist soil to the top of the ground will also prevent moisture loss," Crenwelge says.
Producers may also consider installation of furrow dikes to maximize benefits of irrigation and/or rainfall.
Furrow dikes are small mounds of soil that are mechanically installed in the furrow to create a small basin in front of each dam. When rainfall occurs in amounts exceeding the soil's infiltration rate, furrow dikes hold water in the small reservoir until it can soak into the soil.
Furrow dikes are also used in conjunction with LEPA center pivots to keep irrigation water on the field, which helps reduce water waste ("irrigation tailwater").
Both High Plains Water District and USDA-NRCS personnel recommend that producers check soil moisture conditions in their fields prior to planting.
"The availability and deficit maps show general soil moisture trends. They are another tool to help producers make management decisions prior to planting 2009 crops. However, there is no substitute for taking a core sample of soil in the fields prior to planting to determine if pre-plant irrigation is needed," Crenwelge says.
An illustrated step-by-step procedure to determine soil moisture is found in the High Plains Water District's Water Management Note, Estimating Soil Moisture By Feel and Appearance. It may be downloaded at http://www.hpwd.com/downloads/downloads.asp. Printed copies are available by calling the district office at (806) 762-0181.
"There's an old West Texas saying that 'we're just one day closer to rain.' We certainly hope so but until then, we encourage producers in the district to conserve the residual moisture stored in the soil and to use their groundwater wisely without waste during pre-plant irrigation season," said High Plains Water District Manager Jim Conkwright.