Rice

Home Fertilization Guide Rice

Rice is cultivated over a wide range of soils, with optimal growth in acidic soils with a pH of 5.5-6.5. Rice cultivation makes use of saline and alkaline soils, improving the pathogeneses that make them unsuitable for other crops. The best soils for cultivation under flooding are cohesive soils, which limit water infiltration. On the contrary, water infiltration is intense in light soils with simultaneous leaching and loss of nutrients.

The amount of nitrogen to be used depends on the variety grown, the sufficiency of irrigation water and the crop rotation applied. Nitrogen increases the height, number of panicles and leaf size, factors that are crucial for the final yield of the crop. The total amount of nitrogen required is between 12-16 kg per stremma. 40% is provided in ammoniated non-urate form as a basal fertilizer just before sowing by dispersion and incorporation over the whole field surface. Because rice is sulphur demanding, it is advisable to use nitrogen sulphate fertilizers. The remaining 60% is provided as surface fertilization of ammoniacal non-urate form in 2 doses: 1st dose: 40% of the total quantity in the tillering (25-35 days after sowing) 2nd dose: The remaining 20% just before inflorescence swelling (50-60 days after sowing)

Phosphorus promotes root development during the early stages of plant growth and contributes to early flowering and ripening. The amount of 5-8 kg phosphorus per stremma during basal fertilization is considered satisfactory, provided that the other elements are available.

Potassium increases the resistance of plants to pests, diseases, adverse weather conditions, and sloping, strengthening the stems of the crop. The reaction of plants to nitrogen and phosphorus is increased in cases of potassium sufficiency. The potassium demands of the crop range between 4-6 kg per stremma. All potassium is provided in the basal fertilization except in cases of deficiency, where 50% is provided in the basal

fertilization and the remaining 50% is provided on the surface as potassium sulphate in the tillering.

Regarding trace elements, no common nutrient deficiencies are observed except that of zinc. In cases of deficiency, zinc is provided with the basal fertilizers or 15-20 days after sowing. The availability of zinc in the soil at pH>6 (common in the rice fields of Greece) is limited and requires the foliar application of a chelated form of zinc IDHA 10% with photolysis resistance.