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Posted 2008-07-18 10:12:47
My wife says the opposite, she says the rain will wash away the fertilizer. Who knows? Issangeorge
Posted 2008-07-18 10:54:41
If your there knowan whats your thoughts or other from experiance
I thought just after rain, then again if u put in down dry and no rain what happens to to fertilizer
Posted 2008-07-18 13:09:23
When applying urea, some of the nitrogen will be lost into the atmosphere if it spread on the top of the soil and not worked in. The excess heat makes this happen alot quicker than in a cool climate.
If you just spread the urea on top of the soil, and then do not get rain you will loose up to 30% of the nitrogen; but not more than this! Around 70% will still be available to be washed down when the rains do come.
Compound fertilizers like 15 15 15 etc with nitrogen, potassium and phosphate. Are not highly recommended for side dressing, as the phosphate beng applied is not going to wash down to the reach root zone fast enough to be any real benefit in that season, and is therefore wasteful and unnecessary. Although I know some farmers who swear by side dressing with N,P,K compound fertilizers for potatoes, I disagree with this and only use nitrogen for side dressing or nitrogen and potassium when required, with all phosphate going on planting.
With the compound fertilier there will be no atmospheric losses of phosphate and potassium, and the nitrogen in the compund will react like the urea. Some forms of nitrogen like in DAP 18 46 0 will react maybe about 40% slower with the atmosphere than what urea will.
THE MAIN THING ABOUT SIDE DRESSING FERTILIZER........... IS MAKING SURE THAT IT IS NOT LEFT ON TOP OF THE SOIL, SO THAT NITROGEN IS LOST TO THE ATMOSPHERE. Therefore there are two main ways we can control this..........If you have irrigation capabilities, spreading your fertilizer on the ground and irrigating on the same day is the easy and effective method to applying fertilizer.
If it is a row crop, like corn, cane or cassava etc; there are lots of side dressing machines available. They are usually painted blue with fertilizer box(es), tynes for covering and burying the fertilizer and steel drive wheel out the back (they look exactly like a Thai made corn planter). Unfortunatley most of these blue mahines are a poor design, as it near impossible to get the same amount of fertilizer coming out of each outlet. In Nakon Sawan, there is a company that is making stainless steel fertilizer boxes and using auger feed measuring units, this is a alot better design.
So is it better to put the fertilizer on before or after the rain??
I would have to say before the rain..........but make sure you cover it!!! Becuase if you cover it, the nitrogen will not be lost to the atmosphere, it will sit happily underground until the rain comes. When the rain comes it will be activated alot faster than if you were to apply it after the rain.
TOO EARLY OR TOO LATE.....Again you need to know your soil type and crop well to know the corret timing for sie dress application. If you are too early with your application some of the fertilizer will leech below the root zone, if you are too late the plant may have high demand for the nutrient and suffer from some nitrogen or potassium deficiency.
When ever side dressing fertilizer be careful not apply too higher quantities of fertilizer too close to the roots, as this may cause burning.
I know one guy that lost about 20% of his rubber tree's because the labour (being lazy) applied one large dose of fertilizer right at the base of the tree, instead of what they were instructed to do which was three smaller doses further out around the tree.
Posted 2008-07-18 14:48:40
Apply AFTER a good rainfall when the soil is still very wet. The heavy rains we experience here will wash too much away if applied just before heavy rainfall. If applied to dry soil, urea (present in most combined fertilisers used for cassava) will be lost to the atmosphere. At this stage of your cassava growth, simply broadcast the fertiliser.
Posted 2008-07-21 18:23:14
Thanks SAP,and kownan,
left friday just got back,today,i did it for the bra,inlaw,they spread away from stems then covered after with the small [ETACT] 2 wheel hand held tractors,as was only 6 weeks old casava,
on our 20 rai casava,we put cow manure down before planting and i will wait for rain then am going to put down 50ks 2 rai a against 1 rai,just to see what i get after 14 months,as i intend to buy 100 rai plus later.[ its already 3 months old our cassava]
for our 8 rai of corn we only got 3 1/2 ton compared to 8 ton last year with a lot more rain,price last year 6,000 tonne this yr 7.1700.
last year [8rai] but still got 8 tonne using no fertilizer, but as i said it rained,so i dumped 8 tonne of manure on sunday and will put some zargor bone and skin down as well and see how we go,,planting corn then change to cassava .
we have a dam [pond]so will buy a pump and sprinklers, to again seehow we go, we only brought the 8 rai last yr so maybe thay looked after the land.
thanks again boys.i hope it helps someone.
Posted 2008-07-24 13:41:05
We have about 100 Rai of Cassava.
We combined weeding, ploughing and fertilizer application in one operation, after 3 months growth.
We had workers hand spreading the fertilizer along the centre of the rows.
They were followed by the small hand held tractors that chopped up the weeds,
ploughed the fertilizer into the soil and heaped the soil up onto the Cassava mound.
Luckily there were heavy rains over the following days, so the softened soil absorbed the water quickly,
with little runoff.
So we're confident the fertilizer is right where it's needed.
Also, my BIL made some steel fender-like extensions to the front of the tractors to push the leaves and
branches back as they went along and so avoided catching and damaging the longer branches under the