Saturday, May 30, 2015

Soil tests and growing things - the worst field

Did soil tests on 5 fields, and they should me a variety of different conditions; generally speaking my land is in fair to good shape, with the new land I'm farming in pretty poor shape overall.  Shouldn't be a surprise; it's been cut for hay for a decade with nothing put back on the land, and so the soil is pretty weak overall.

Soil test for top half of new acreage
This field needs the most help to get it back into production.  Lots of lime - 6200lbs per acre is what is reccomended, and needs lots of potassium and phosphorus.  So how do you fix that?  Well...
Applying lime with the spreader
 You order up 35 tons of lime, and you load up the 10' spreader, and have the nephew earn his summer spending money by having him listen to an audiobook while he drives around and around.
Applying lime with the nephew
I calculated the amount of lime as about 1lb per 8x10' area; used a tarp under the spreader, collected it, weighed it, and adjusted the setting.  6 hours of tractor passes later the field is limed and ready for planting.    

The fertilizer issue is a little more of a problem.  First, it's expensive, and second, there's an application issue.  So I'm going to apply fertilizer when I plant the corn; the corn planter will both plant the corn and deposit dry fertilizer in the row.   The corn will use some of the nutrients, some will stay in the soil, and I'll do a soil test at the end of the year and see what the soil is like then.  the lime will definitely change the PH.  

The corn is also an indicator of general fertility.  At harvest I'll be able to look at the field and tell where the problem areas are by the growth of the corn.  

So the lime was $1050 ($30/ton).  the fertilizer mix for the planting was another $1600.  The corn seed itself was about $1000.   I'll have a total for tractor time when we get it all done, but it looks like my costs are going to be something like $250/acre;   that seems high, but as long as I'm under $1,000/acre I'm paying less than I would if I purchased this corn from the local feed mill, so although I hate writing the checks, the long-term still looks doable.  


Rich said...

Just glancing at that soil test it seems to me that they are recommending a lot more fertilizer than I would think is needed for a 140 bu. corn crop.

Off the top of my head and after looking at the K-State Corn Production Guide (, a 140 bu. corn crop needs about 70 lb. of total P and 85 lb. of total K.

And, if I read it right, if you have a 9.9% OM level then theoretically you should have about 45-65 lb. of P per year coming from your OM (which doesn't always show up in a soil test).

Bruce King said...

Rich, thank you for pointing this out. It didn't even occur to me that lower bushel corn would take less nutrient support, but it makes perfect sense. The fertilizer values they're using are probably for closer-to-200 bushel corn. As it is I'm applying the fertilzer in dry form with the planter, so I'm only fertilizing a narrow strip where the corn itself is planted, not every foot of the property. I'll retest the field after the corn is harvested and see what the conditions are like after the corn has drawn what it needs. After the corn I'm going to probably plant some sort of small grain; barley, oats, wheat, something like that as a cover crop, and then replant something more long-term next spring.