Achim Dobermann, deputy director general for research at the International Rice Research Institute (IRRI; http://irri.org ), and Leigh Vial, head of IRRI's experiment station, find that seed sowing is not that easy when planting in a 25 x 100-meter field on IRRI's research farm.
Commentary from Mr. Vial: "On 6 January, we tried the drum seeder, but it quickly sunk to the axle in deep mud. This is a special kinda dirt!
We tried larger diameter wheels to keep the metering drums out of the mud, but alas no help. We even tried to lift the seeder a little by pulling the tow-bar a little higher than normal (logical for a six-foot-something German), but this helped little and was leading us both straight to a physiotherapist if we persisted. We learned that the drum seeder is not applicable to all
Plan B was broadcasting the next morning (7 January) at 80 kg/ha. After a calibration run (scales stolen from Achim's kitchen like all good farmers do...), we both got our rates about right, but getting a uniform spread is a little bit of an art. The shoots are quite long now, which may help where the water is lying. It took two of us about 30 minutes to broadcast the 0.25 ha; slow, but heaps quicker than transplanting.
We spent the last hour carving extra ditches to drain the field, as removing the last centimetre of water is tough. Gravity offers little at this point. I dearly wish we could design for a small slope across the field -- say 0.1% or more - to convince the water to go somewhere with conviction. With a laser it may be possible next time, but maybe in this system this slope would disappear too quickly.
8 January: Praying for dry weather... I am sitting here listening to MORE rain on the roof and my heart is sinking. I can see why breeding for a seed that happily germinates and grows from under an inch or two of water makes real sense! The drains are doing admirably in getting water off the field, but deep in my cockles I fear a failure.
9 January: Maybe not...it is touch and go, but I see a few pale shoots emerging from shallow puddles. We will press on and apply butachlor at 1.7 L/ha this afternoon, then snail control once conditions permit.
International Rice Research Institute
6 years ago