Rainfed rice - IRRI books - International Rice Research Institute
Rainfed rice - IRRI books - International Rice Research Institute
Rainfed rice - IRRI books - International Rice Research Institute
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Minimal Fertiliser Use<br />
R<br />
ainfed <strong>rice</strong> is grown under varied ecological situations ranging from<br />
upland dry to deepwater and flooded situations. Most rainfed <strong>rice</strong><br />
farmers are by and large resource-poor. Frequent droughts and<br />
floods involve a lot of risk in <strong>rice</strong> cultivation, so most farmers do not apply<br />
the recommended doses of fertilisers. In fact, even when farmers do use<br />
chemical fertilisers, they do so in small quantities.<br />
Fertiliser use efficiency (FUE)<br />
Scheduling of fertiliser application affects<br />
fertiliser use efficiency to a great extent. The<br />
proper scheduling of fertiliser application is<br />
especially critical when low levels of<br />
fertiliser are used, such as in Assam.<br />
Upland<br />
50% of the recommended fertiliser<br />
dose available<br />
1. Apply half nitrogen and full phosphorus<br />
and potassium as basal through plough<br />
sole placement or by ferti-seed drill.<br />
Topdress the rest of nitrogen after<br />
weeding about 20-30 days after sowing<br />
depending on rainfall. Under inadequate<br />
rains, apply nitrogen through foliar<br />
spray using 2-3%, urea solution. In highrainfall<br />
areas of Assam, place half of<br />
potassium and topdress the rest with<br />
nitrogen.<br />
2. If farmers can manage only 20 kg of<br />
nitrogen/ha, it should be topdressed at<br />
25-30 days after sowing depending on<br />
rainfall or applied by foliar spray of 2-<br />
3% urea solution when rain is<br />
inadequate. Remove weeds before<br />
applying fertiliser.<br />
Optimum doses (N: P 2 O 5 :K 2 O)<br />
Uplands<br />
40-60:30:20<br />
Shallow land 80-100:60:40<br />
Medium deep 60-70:40:20<br />
Deep 40-60:30:0<br />
Very deep and floating 20-30:0:0<br />
Advantages of fertiliser placement under<br />
upland conditions<br />
Fertiliser is placed in the root zone to improve<br />
availability to the crop.<br />
Nutrient losses due to volatilisation,<br />
denitrification and runoff are minimised.<br />
Competition for nutrients by weeds is reduced<br />
due to unavailability of nutrients at the soil<br />
surface.<br />
Prolonged availability of nutrients to crop<br />
plants.<br />
Reduced phosphorus fixation, especially in<br />
acidic soils.<br />
Increased fertiliser use efficiency.<br />
Higher yield.<br />
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