Effect of Long Term Phosphorus Fertilizer Application on Phosphorus Availability and Cd Accumulation in Rice Soils (Oryza sativa L.)
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Date
2013
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
Rice occupies approximately 33 % of the total cultivated area in Sri Lanka accounting to 0.78
million hectares (Central Bank of Sri Lanka, 2010). Plant nutrients are essential for the
production of crops and in term of healthy food for the world’s increasing population. In that
context, phosphorus (P) is an important nutrient in rice cultivation. P is directly absorbed form
soil and makes up 0.1% - 0.4% of the dry matter in plants. It involves in carbohydrate
breakdown for energy release, cell division and transfer of inherited characters. P stimulates
early root growth and development, hastens maturity of plant, improves seed production and
involves in energy transformation. Since supply of P from soil is not enough to obtain higher
grain yields, farmers are advised to apply P fertilizer into soil. These synthetic fertilizers carry
lot of heavy metals such as Cd as contaminants. Scientists are of great interest at the moment of
the contamination of heavy metals to paddy fields through P fertilizer especially super
phosphate (TSP). Cadmium (Cd) is a toxic heavy metal and is also known as one of the major
environmental pollutants. Cd is dissolved in water, taken by crops, transferred to human body
by ingestion causing health problems. This research was conducted to study the effect of P
fertilizer application in the long term basis on soil fertility status and grain yield of paddy.
Methodology
The study was conducted at Rice Research and Development Institute Batalagoda situated in the
low country intermediate zone IL1 agro ecological region of Sri Lanka (longitudes of 800 and
810 and latitude of 70 and 80 at an elevation of 65 meters above sea level). Soils of the
experimental site belong to Kurunagala soil series and great soil group of Psummentichupludult.
Treatments namely: no P fertilizer (T1); seasonal P fertilizer application (T2); alternative
seasonal P application (T3) were used and arranged in Randomized Complete Block Design
(RCBD) with four replicates. P fertilizer rates added to the above experiment were based on the
recommendation given by the Department of Agriculture (Department of Agriculture, 2001).
respectively. Soil samples were analyzed for
available P and total P contents. Plant samples were analyzed for plant P contents. To determine
Cd accumulation in soil, straw, seeds, plant and soil samples were analyzed. Having air dried
and passed through 2 mm sieve, each sample was thoroughly ground into fine powder and total
P, available P and Cd were measured.
Description
Keywords
Agriculture, Export Agriculture, Crop Production, Crop Production Technology, Soil Science, Rice Research Development