English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

A 3-year investigation was conducted by the U.S. Geological Survey in cooperation with the Puerto Rico Department of Agriculture to determine the water required and used (both consumed and applied) for irrigation in the rice-growing areas of Vega Baja, Manati, and Arecibo along the north coast. In addition, the investigation evaluated the water resources of each area with regard to the full development of rice farming areas. Based on experiments conducted at selected test farms, water required ranged from 3.13 to 5.25 acre-feet per acre per crop. The amount of water required varies with the wet and dry seasons. Rainfall was capable of supplying from 31 to 70 percent of the water required for the measured crop cycles. Statistical analyses demonstrated that as much as 95 percent of rainfall is potentially usable for rice irrigation. The amount of water consumed was found to differ from the quantity required at selected test farms. The difference between the amount of water consumed and that required was due to unaccounted losses or gains, seepage to and from the irrigation and drainage canals, and lateral leakage through levees. Due to poor water-management practices, the amount of water applied to the farms was considerably larger than the sum of the water requirement and the unaccounted losses or gains. At present, rivers within the rice growing areas constitute the major water supply for rice irrigation. Full development of these areas will require more water than the rivers can supply. Efficient use of rainfall can significantly reduce the water demand from streamflow. The resulting water demand, however, would still be in excess of the amount available from streamflow. Ground-water development in the area is limited because of seawater intrusion in the aquifers underlying the rice-growing areas. Capture of seepage to the aquifers using wells located near streams, artificial recharge, and development of the deep artesian system can provide additional water for rice irrigation. INTRODUCTION Commercial scale rice farming began in Puerto Rico in 1980, under the direction of the Rice Corporation of the Puerto Rico Department of Agriculture. Principal rice-growing areas in Puerto Rico are located along the north coast and include 15,000 acres within the valleys of Vega Baja (A,000 acres), Manati (5,000), and Arecibo (6,000 acres) (fig. 1). Irrigation plays a critical role in rice farming because the plants require large amounts of water during their seeding and vegetative growing stages for maximum yields (Vicente-Chandler and others, 1977, p. 30). In 1983, the U.S. Geological Survey began a cooperative a study with the Puerto Rico Department of Agriculture to investigate the amount of water required and used for irrigation in the rice growing areas of Vega Baja, Manati, and Arecibo. Water required depends upon the irrigation method used, and the water loss by infiltration and evapotrahspiration. The water used (consumed and applied) will almost always be different from that required because of unaccounted losses or gains and water mismanagement. The availability of ground-water and surface-water resources to supply the water demanded by rice irrigation in terms of full development of each rice-growing area was also evaluated during the investigation. /s^ I .^F«*"* \ \ .r^ [ .^ / -. WS'U Figure 1.--Location of the rice growing areas along the north coast of Puerto Rico. INTRODUCTION (Continued) The investigation included representative farms from the different soil types in each area. Infiltration, evapotranspiration, and inflow and outflow of irrigation water for each test farm were measured. Measurements were conducted over two crop cycles: one during the dry season and one during the wet season. Climatological data (temperature, pan evaporation, wind velocity, and rainfall) were collected daily in each rice-growing area to determine the role of climate on water required for rice irrigation and the amount of rainfall available to augment the existing water supply. Data generated from previous investigations by the U.S. Geological Survey were used to evaluate the water resources of each area.

Water required, water used, and potential water sources for rice irrigation, north coast of Puerto Rico