Abstract
Available soil-phosphorus (P), exchangeable soil-potassium (K), soil pH and soil Electrical Conductivity (EC) affect rice production and are highly variable in nature mainly due to the variability in water availability. Therefore, experiments were conducted to find out the variability of some important soil chemical properties of rainfed lowland paddy fields and their effect on land suitability for rice cultivation in the Dry (Mahananeriya), Intermediate (Ibbagamuwa) and Wet (Alawwa) regions in the Kurunegala District of Sri Lanka. Randomly collected soil samples from the above three areas were analyzed for available soil-P, exchangeable soil-K, soil pH (1:2.5) and EC (1:5). Thematic maps for each parameter were prepared using Inverse Distance Weighted interpolation technique. Weighted sum technique was used to overlay maps to prepare the suitability map as Marginally Suitable, Moderately Suitable, Suitable and Highly Suitable. Results showed that the available soil-P and EC levels are preferable for rice cultivation in the rainfed lowland paddy fields in all three regions. Even with this situation, the potential productivity of the lands cannot be obtained due to variability of soil pH and exchangeable Potassium contents. Soil pH and the exchangeable soil Potassium in all rainfed paddy areas of Alawwa is far below the optimum levels for paddy cultivation. In terms of these soil chemical properties, 42% and 32% of rainfed paddy fields in Ibbagamuwa and Mahananeriya regions, respectively, are either highly suitable or suitable but 79% land extent of the rainfed paddy in Alawwa is marginally suitable for rice cultivation. Therefore, a blanket recommendation of remedial measures cannot be introduced to improve productivity of the rainfed paddy fields in these regions while site-specific remedial measures would help to overcome the problems of specific soil chemical properties. Tropical Agricultural Research Vol. 26 (3): 506 – 516 (2015)
Highlights
Almost all paddy fields in Sri Lanka are cultivated with high yielding rice varieties (HYVs)
A 1:10000 analogue and digital maps of the Kurunegala District prepared by the Survey Department of Sri Lanka were used to extract and map the paddy areas using Geographic Information System (GIS)
Rainfed paddy areas were extracted for Mahananeriya, Ibbagamuwa and Alawwa agrarian service centre (ASC) with the help of GIS technology
Summary
Almost all paddy fields in Sri Lanka are cultivated with high yielding rice varieties (HYVs). The HYVs need high rate of nutrient supply to produce optimum yield benefits (Abeysiriwardene and Sandanayake, 2000). Factors that reduce nutrient availability and absorption will adversely affect rice production. Land Suitability for Rice Cultivation soil-Phosphorus (P), exchangeable soil-Potassium (K), soil pH and soil Electrical Conductivity (EC) are some of the important soil chemical properties that affect rice production. These chemical properties are highly variable in nature mainly due to variability in water availability
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.