1,726 research outputs found
Irrigation Water Management for the Next Decade
Irrigation water management is becoming more important as irrigation
competes for limited water supplies and energy, and as lands throughout
the world degrade and decline in productivity because of poor water management.
This paper discusses the state-of-the-art of irrigation water
management and its effects on water and energy conservation, current
trends and new developments in on-farm irrigation systems, recent developments
in water use-crop production technology, new irrigation scheduling
technology, and lists expected changes in technology
Discussion: Irrigation Requirements of Lawns
Engineers must estimate consumptive
use although, in many cases, only limited supporting data are available. T.
Quackenbush and J. T. Phelan have presented a method for estimating water
requirements of lawns based on a modified Blaney-Criddle formula. They have
stated that the irrigation water requirements can be computed using the modified
formula and that they believe that reasonable estimates can be made for
lawn grasses. However, no tangible evidence was presented that confirms or
supports these statements. The modern practicing engineer is aware that
estimating procedures do not yield precise answers. The engineer must know
the confidence limits to be expected of an estimating procedure, i.e., will the
calculated monthly consumptive use values be within ± 10% or ± 15% of the actual
consumptive use most of the time? A comparison between calculated consumptive
use using the proposed procedure and accurate lysimeter data not
used in the original development of the empirical procedure would provide this
information. At the least, a comparison between calculated values using the
proposed procedure and the original data from which the procedure was derived
would indicate its reliability
Advances in Conserving and Recycling Water
Major efforts to conserve water
are most evident in areas where
water supplies now limit crop
production, or where available supplies
can be expected to decrease
severely in the near future. Use
of water-conserving practices in
these areas may be stimulated by
legal actions that prohibit irrigation
tailwater from entering barrow
pits along roadways, because of
expensive silt removal, or from
entering shallow lakes where water
may be wasted through evaporation
Irrigation Scheduling for Farm Crops
This paper summarizes the needs of managers of modern irrigated farms and
the status of a user-oriented irrigation-scheduling computer program designed
to provide managers with estimates and predictions required for optimum irrigation
water management
Discussion: Estimating Evaporation from Insolation by R. K. Lane
Formula and notes to estimate evaporation from insolatio
Changes in Nitrate-Nitrogen Concentration in Sugar Beet Petioles as Influenced by Irrigation and Fertilizer Practices
Sugar beets must be properly irrigated and fertilized to maximize sugar
production. Both yield and sugar content can be materially altered by water
or fertilizer deficiency or excesses (4, 5). Farm operators must carefully
manage fertilization and irrigation to obtain the greatest net return from
sugar beets
Effects of Alfalfa, Crop Sequence, and Tillage Practice on Intake Rates of Pullman Silty Clay Loam and Grain Yields
The High Plains of Texas is one of the largest irrigated areas in the
United States. Most of the 5.7 million acres irrigated in Texas
(1959 census) is concentrated in the High Plains. The area is unique
because most of the irrigated land is of one soil series-Pullman.
Pullman soils represent over 5 million acres of the “hardlands” in the
Southern High Plains of Texas, New Mexico, and Oklahoma.
The term “hardlands” is used extensively when referring to the
High Plains because of the soil characteristics of the area. The soils
are mostly clay loams and silty clay loams. The have low intake
rates, are dense, and become very hard and difficult to till when dry.
The differences between the clay loams and silty clay loams are
minor. The physical characteristics of a given layer of these Pullman
soils are very uniform over large areas, some as extensive as several
counties
Evapotranspiration and Soil Moisture-Fertilizer Interrelations with Irrigated Grain Sorghum in the Southern High Plains
In 1956 and 1957 grain sorghum represented
37 percent of the harvested crop acreage in Texas. The largest concentrated area of sorghum
is in the High Plains where the proportion of
sorghum irrigated increased greatly during the
drought years of the 1950's. In 1959 the monetary
value of irrigated grain sorghum was estimated
to be about $100 million.
As reported by the U.S. Census of Agriculture
the acreages of irrigated grain sorghum harvested
in the 42-county High Plains area in 1950, 1954,
and 1959 were 387,000, 1 1 006,000, and 1,224,000
acres, respectively. The irrigated grain sorghum
acreage in the eight counties—Castro, Deaf
Smith, Floyd, Hale, Lamb, Lubbock, Farmer,
and Swisher—represented over 80 percent of the
total in the High Plains in 1954 and 1959
Predicting the Nitrogen Needs of Sugar Beets by Petiole Analysis
Sugar beets are grown extensively
in areas where fertilization and irrigation
can be regulated to maximize
sugar production and net returns per
unit area. The yield and sugar content
of sugar beets can be materially
affected by either deficiencies or excesses
of water and fertilizer. Nitrogen,
in particular, has a great effect
on yield and sugar content of beets.
Inadequate nitrogen limits root yield.
On the other hand, excess residual or
applied nitrogen stimulates top growth
and reduces root sugar percentage
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