Mahbub Alam

SUBSURFACE DRIP IRRIGATION USING LIVESTOCK WASTEWATER: DRIPLINE FLOW RATES

Using subsurface drip irrigation (SDI) with lagoon wastewater has many potential advantages. The challenge is to design and manage the SDI system to prevent emitter clogging. The objective of this study was to measure the flow rates of five types of driplines (with emitter flow rates of 0.57, 0.91, 1.5, 2.3, and 3.5 L/h/emitter) when used with lagoon wastewater. A disk filter with openings of 55 µm (200 mesh) was used and shock treatments of chlorine and acid were injected periodically. During the 1998 growing season, 530 mm of wastewater were applied through the SDI system and 390 mm were applied in 1999. During the growing seasons, the two lowest flow rate emitter designs decreased in flow rate, indicating that some emitter clogging had occurred. The magnitudes of the decreases were 15% and 11% of the original flow rates in 1998 and 22% and 14% in 1999 for the 0.57 L/h/emitter and 0.91 L/h/emitter driplines, respectively. After the winter idle period, the flow rates of both driplines returned to the initial flow rates. The three emitter designs with higher flow rates showed little sign of clogging; their flow rates decreased by 4% or less through both growing seasons. Observations showed that the disk filter and automatic backflush controller performed adequately in 1998 and 1999. Based on these preliminary results, the use of SDI with lagoon wastewater shows promise. However, the smaller emitter sizes (0.91 L/h/emitter or less) may be risky for use with wastewater and the long-term (greater than two growing seasons) effects are untested.

Application of a Linear Move Sprinkler System for Limited Irrigation Research

A linear move sprinkler system was adapted to apply different amounts of water to random patterns of research plots in limited irrigation experiments. This is a further application of existing modified center pivot and linear move sprinkler systems for specialized research. Research outcomes will provide the technical foundation for policy decisions dealing with water allocations on a regional scale and the foundation for information to irrigators for making water allocation decisions on their own operations.

Twenty Years of Progress with SDI in Kansas.

This paper will summarize research efforts with subsurface drip irrigation in Kansas that have occurred during the period 1989 through 2009. Special emphasis will be made on brief summaries of the different types of research that have been conducted including water and nutrient management for the principal crops of the region, SDI design parameters and system longevity and economics. Annual system performance evaluations have shown that dripline flowrates are within 5% of their original values. Economic analysis shows that systems with such longevity can be cost competitive even for the lower-valued commodity crops grown in the region.

Impact of Collector Size and Spacing on Center Pivot Uniformity Evaluations

Field scale evaluations of center pivot sprinkler irrigation systems for water distribution uniformity have been conducted as part of the Mobile Irrigation Lab project (MIL) in Kansas for over ten years. This data base was used to demonstrate the effect on the coefficient of uniformity calculation by using subsets of the data base with increased spacing between collectors. During field evaluations, a portion of several systems were sampled using different collector sizes.

A Mobile Irrigation Lab (MIL): Bringing Education and Technical Assistance to the Farm in the Computer Age

Successful transfer of information and technology to farmers and farm managers can occur in many ways. However, improved adoption of technology occurs when individuals have first-hand experience with the technology. This involves hands-on training and in-field evaluation using computer-based decision-making and analysis tools. The goal of the mobile irrigation lab (MIL) is to bring high tech training and evaluation opportunities to the field. A classroom and equipment storage trailer is equipped to allow one-on-one and small group training, while at a site to gather field information. The initial emphasis of MIL is irrigation scheduling and evaluation of center pivot sprinkler uniformity. Irrigated agriculture contributes heavily to the economy of Kansas and is especially important in western areas of Kansas. In many irrigated areas, water supplies are being depleted. Adoption of best management practices can help extend the life of existing water supplies.

Technology Transfer: Promoting Irrigation Progress and Best Management Practices

Educational efforts promoting irrigation best management practices are designed to increase adoption of these practices and increase public understanding of the importance of irrigation. They increase visibility and impact of the Ogallala Aquifer Program and promote affiliated research and extension programs to agricultural producers, consultants and water resources managers. Building upon existing programs and collaborations, successful programs are being expanded to accommodate additional audiences and applications. Improved quality, effectiveness and efficiency of educational programs are made possible through improved communication and complementary expertise of the collaborators. A variety of methods and media (electronic and print; modular educational packages; mass media; and traditional Extension field days and workshops) are being used to reach an expanding and diverse audience. Evaluation surveys and levels of participation in education events indicate that audience response has been very positive.

Impact of Technology and Policy on Sustainable Agricultural Water Use and Food Security

Water, soil, air, and sunlight are integrated components of food production. However, water is unique in that humans have been able to manipulate the supply of water, particularly for agrarian applications. A variety of technological innovations in plant breeding, biotech traits, and agronomic improvements have resulted in improved water use efficiency or engineering breakthroughs that result in increased sustainable irrigation techniques. Common to these innovations is investment in science to discover the solutions to the challenge of feeding the estimated 9.5 billion people expected to be living by the year 2050. Water sustainability will be an important factor that has to be addressed, not just in the USA, but globally. As water availability becomes an even more limiting factor, water legislation, regulation, and policy will play an ever-more important role. Managing the water requirements for food production, urban, recreational, and energy and industrial uses will require policy decisions at various levels of government.

Effect of Irrigation Ending Date on Corn Yield and Irrigation Scheduling for Water Conservation

The results from a two-year field study indicate that the corn growers of western Kansas may not have to irrigate until black layer formation, as is the current practice. With the decline of Ogallala aquifer groundwater level and rising fuel cost any reduction of pumping makes economic sense. The first irrigation ending date was on August 10-15, corresponding to denting and starch layer formation of ¼ to ½ towards the germ layer resulted in yield that averaged 7 bushels per acre less than the second ending date on August 21-22, which corresponds to starch layer at ½ to ¾ towards the germ layer. However, continuing irrigation until September 1, corresponding to the start of black layer formation, improved yield by only 2 bushels per acre. A statistical analysis over the two years of data indicates that the first ending date is different from the last ending date, but the second ending date is not different from either first or last ending dates. Economic sensitivity tests show that irrigating until the formation of starch layer at ½ to ¾ towards germ layer is feasible with a corn price of

Using subsurface drip irrigation for alfalfa

2 per bushel and

Subsurface drip irrigation for alfalfa.

6 per inch pumping costs. However, irrigating past this stage of grain development is not feasible even with