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close this bookLow-external Input Rice Production (IIRR, 292 p.)
close this folderIntegrated nutrient cycling
View the document(introduction...)
View the documentIntegrated nutrient cycling in lowland rice production: an ecosystem approach
View the documentNutrient cycling on a basic irrigated or rainfed rice farm
View the documentUsing soil test values to determine fertilizer needs for rice
View the documentFertilizer placement in wetland rice
View the documentUsing limited nitrogen fertilizer with HYVs
View the documentTreatment for zinc deficiency in lowland rice
View the documentFertilizer from livestock and farm wastes
View the documentChicken manure for lowland rice
View the documentFood, fodder, fertilizer and fuel from paddy dikes
View the documentUsing rice straw for lowland rice farming
View the documentAzolla: green manure profile
View the documentUsing azolla as fertilizer for lowland rice
View the documentMultiplying the azolla
View the documentTroubleshooting common problems in azolla production
View the documentGreen leaf manuring in lowland rice
View the documentGreen manure utilization in lowland rice
View the documentSesbania aculeata: a bio-fertilizer source for lowland rice
View the documentIndigofera: green manure profile
View the documentCrotalaria: green manure profile
View the documentLablab bean: cover crop/green manure profile
View the documentRice bean: green manure profile
View the documentSesbania spp.: green manure profile
View the documentAnimal and green manure practices among the Mangyans (Alangan tribe in Mindoro)
View the documentWaste management practices (Tuwal and Ayangan tribes in Ifugao)

Using limited nitrogen fertilizer with HYVs

Even when using biofertilizers, farmers often use small amounts of chemical nitrogen (N) fertilizer to obtain increased yields. One of the simplest, lowest-cost ways to increase the effectiveness of these small amounts of fertilizers is by applying them at the right time and in the right manner. With good fertilizer management, yields can be increased by 0.50.8 ton/ha over poor management practices even when using small amounts (15-30 kg N/ha) of fertilizer.


Using limited nitrogen fertilizer

· Best split method.

The best method of fertilizer application for lowland rice is still the best Split where 2/3 of the nitrogen and all the phosphorous and potassium fertilizers are broadcast and incorporated thoroughly into the soil without standing water during final harrowing. The remaining 1/3 is top-dressed 5-7 days before panicle initiation (DBPI) of the crop. This should be practiced if the rate of application is 60 kg N/ha or more.

· Time of application if less than 60 kg N/ha is available.

Considering the limited availability of fertilizers due to high costs, the rates of application may be as low as 13 kg N/ha. The table on the other page shows how to use limited N fertilizer with the commonly grown high-yielding rice varieties.

· Procedure when basal application of nitrogen fertilizer is missed.

Topdress one half of the total N requirement at 10-15 days after transplanting for early-maturing varieties (100-1 15 days) and 20-25 days for medium-maturing varieties (116-135). The remaining half should be applied 5-7 DBPI.

· Use of green manure in combination with chemical fertilizers.

Research has indicated that in addition to supplying the green manure N. using green manure can also increase the efficiency of chemical fertilizers used. When using minimal amounts of chemical N (30 kg/ha N or less) with a green manure, all chemical N should be applied 5-7 DBPI.

REFERENCE: Rice Production at Cost-Reduced Technology. Compiled by: Damaso Callo, Jr., Rizalino Dilag, Jr., Jesus Sumangil and Rustica Bautista.


FERTILIZER MANAGEMENT:

Amount of Nitrogen

Method of Application

If only 30 kg/ha N (or less) is available (1 1/2 bags 45-0-0 or 3 bags 21-0-0)

No basal application should be made. The entire amount should be applied into 5 cm of water at 5-7 days before panicle initiation(5-7 DBPI).*

If only 40 kg/ha N is available(2 bags 45-0-0 or 4 bags 21-0-0)

20 kg N/ha (1 bag 454-0 or 2 bags 21-04) should be applied to a puddled field with or without any standing water and thoroughly incorporated into the soil and water is introduced 4 days after transplanting (DAT). The remaining 20 kg N/ha is to be applied into 5 cm of water at 5-7 DBPI.

If only 50 kg/ha N is available (2 1/2 bags 45-0-0 or 4 bags 21-0-0)

30 kg/ha (1 1/2 bags 45-0-0 or 3 bags 21-0-0) should be applied to a puddled field without any standing water and thoroughly incorporated into the soil and water is introduced 4 DAT. The remaining 20 kg N/ha is to be applied into 5 cm of water at 5-7 DBPI.

If only 60 kg/ha N is available(3 bags 45-0-0 or 6 bags 21-0-0)

40 kg N/ha (2 bags 45-04 or 4 bags 21-0-0) should be applied to a puddled field without any standing water and thoroughly incorporated into the soil and water is introduced 4 DAT. The remaining 20 kg N/ha is to be applied into 5 cm of water 5-7 DBPI.

Note: Beyond 40 kg N/ha, always split the application of fertilizer.