Agriculture Reference
In-Depth Information
window of opportunity for photosynthesis since the life cycle is truncated,
whileboth heat and drought stress may inhibit growth directly at the meta-
bolic level. This ultimately is responsible for lower productivity of crops.
As frequency of drought like situations is increasing in many areas, ef-
ficient irrigation technology like drip or sprinkler irrigation can play a
major role in improving productivity of crops not only in drought-prone
areas but also in areas receiving normal rains. Drought and salinity are
the major and most widespread environmental stresses that substantially
constrain crop productivity in bothnonirrigated and irrigated agriculture.
Irrigation management practices used to increase crop outputs exacerbate
the detrimental impact of salinity in agriculture. In the recent years, the
more emphasis has been laid on microirrigation techniques. In majority
of the crops, yields for micro irrigation systems were better than surface
method of irrigation. Micro irrigation system was found to result in 30 to
70% water savings as compared to traditional irrigation methods (flood-
ing/furrow or check basin) in various orchard crops and vegetables along
with 10 to 60% increases in yield. Mulching with drip further enhanced
the crop yield to the tune of 10-20% and controlled weeds up to 30-90%
(Rajput and Patel, 2008).
Fertilizer solutions can be injected into the irrigation system (ferti-
gation) in commercial crop plantings to avoid stress and poor growth of
plants. The water (and some of the fertilizers present) can then be recycled
by pumping it back out of the holding tank or pond, after some of the im-
purities (sand and silt) have settled out. Recycled water has actually been
shown to improve plant growth. In experiments with more than 100 spe-
cies of ornamentals grown in 2.8 L containers, the mean relative growth of
plants irrigated with continuously recycled water was 103% over that of
the control. Another way to reduce runoff is to use pulse irrigation. In this
system, instead of applying one heavy watering daily, a small amount of
water is applied five or six times during the day. Very little water escapes
from the container or runs off from the field. The production advantage to
this is that less fertilizer has to be applied, because there is less leaching.
Plant growth may be more effectively maximized by reducing moisture
stress than by increasing fertilizer concentration. A fertilizer concentration
ranging between 50 and 200 mg/L of nitrogen gives good results for potted
plants. Sufficient evidences are available to show that water stress might
limit growth more frequently than does limited nutrition under container
production of flowering and foliage plants.
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