Session 18. Water and Energy Conservation with Microirrigation
Simulated Crop Water Use, a GIS Approach
P. Papajorgji, F. S. Zazueta, J. N. Xin, C. Moore
A Geographic Information System (GIS) based system to estimate spatially distributed water requirements for agricultural irrigation is described. AWUGS (Annual Water Use Geographic Survey) contains several components. The database component was developed in the MicroSoft (MS) Windows environment, and the GIS component was developed in the UNIX environment. Several spatial databases including political boundaries, district boundaries, agricultural areas, and climatic zones were created to estimate irrigation requirements using GIS tools. These database layers were overlaid to create more than 50 thousand working polygons. A simulation was carried out for each of the working polygons. Daily and monthly water budget models were used to estimate monthly irrigation requirements. Results obtained for each working polygon were aggregated at county and district levels. The system provides a tool by which sensitivity analysis to water savings resulting from irrigation system conversions to microirrigation can be conducted.
Keywords: GIS, irrigation requirements, database, simulation
Abstract taken from paper found on pages 532 to 537 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
*******
Microirrigation Conservation Project on Quincy Tomatoes
Ben F. Castro, Bobby R. Durden, Steve M. Olson, Fred M. Rhoads
Microirrigation of mulched staked tomatoes (Lycopersicon esculentum Mill.) grown for the fresh market was monitored at six growers fields in Gadsden County, Florida during two seasons. Tensiometers were placed at 15 cm and 30 cm depths to record soil water tensions in the drip line, in the bed center and on the side opposite of the drip line. Pan evaporation and rainfall data were collected at grower sites. Irrigation volumes were recorded daily for each grower. Growers provided irrigation management and supplied harvested yield data. During the fall crop growth period, irrigation water use by growers ranged from 18 cm to 41 cm, while during the spring crop period, irrigation ranged from about 23 cm to 38 cm. Differences in irrigation usage between growers was partly due to differences in local rainfall and pan evaporation amounts. Yield was lowest where the highest irrigation level occurred.
Keywords: Microirrigation, Lycopersicon esculentum, Drip irrigation, Trickle irrigation
Abstract taken from paper found on pages 538 to 543 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
*******
Intake Screen Plugging Effects on Microirrigation Pump Station Performance
Brian J. Boman and Marion L. Parsons
Intake screen plugging was monitored on a microirrigation system using a diesel-powered pump. The intake screen for the 0.59 m2 sec-1 (2500 gpm) pump station consisted of PVC pipe with 0.76 mm (0.030 in.) wide slots having a total open area of 0.61 m2 (6.6 ft2). The slotted pipe was plugged using tape to cover 18%, 36%, 54%, 72%, and 90% of the slots to simulate plugging by algae. Fuel consumption was measured for each set of conditions. The rpm required to achieve 207 kPa (30 psi) discharge head remained at 1650 rpm through 54% blockage. It was necessary to increase rpm to 1693 at 72% blockage and 1805 rpm at 90% blockage to achieve the same discharge head. Fuel consumption remained at 15.1 L hr-1 (4.0 gph) until the average velocity through the intake screen exceeded 0.61 m sec-1 (2 fps). The fuel consumption increased 4% when the open area was reduced to 0.17 m2 (1.8 ft2) and 18% when the open area was reduced to 0.06 m2 (0.67 ft2).
Keywords: pumps, maintenance, efficiency, intake screen, fuel consumption
Abstract taken from paper found on pages 544 to 549 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
*******
Application of Microirrigation Technology to Major Irrigation Projects
N. R. Sawleshwarker
Adoption of microirrigation systems is often limited to local small resources such as wells because of the huge initial costs of the distribution network of pipes and tubes and also because of continuous depletion of the ground water table. The major alternative irrigation system also suffers owing to failure of rains. "Gravity Fed Drip Irrigation System" can provide answers to many problems posed by microirrigation systems like Drip Irrigation and gravity flow surface irrigation practiced on major irrigation projects. An attempt is made in this paper to design and construct a "Gravity Fed Drip Irrigation System" in the Jayakwadi Irrigation Project on the Godavari river in Maharashtra State of India.
Keywords: Control structures, drip irrigation, gravity irrigation
Abstract taken from paper found on pages 550 to 551 in Proceedings of 5th International Microirrigation Congress, April 2-6, 1995, Orlando, Florida. American Society of Agricultural Engineers, 2950 Niles Road, St. Joseph, Michigan 49085-9659, USA. Phone: 616-429-0300 FAX: 616-429-3852 EMAIL: HQ@ASAE.ORG
