soil book and corn question plus

[Sprinkraft at aol.com]

Typically corn root worms are a problem in fields that are not rotated out of 
corn after one year's corn crop and planted to another crop like beans, or a 
grass-grain like oats, wheat or barley. Many farmers, everywhere, plant corn 
on corn ground in successive years and end up with infestations, just as many 
other farms growing other crops like that, for example, carrots on carrot 
ground without an intervening crop in between.

In the US, there is a lot of pesticide used on root worms. 

Its difficult to assay the problem without a bit more info, like acreage 
involved, dependence on corn as a family staple or as a crop to sell, and the 
neighboring land use may also indicate that crop rotations are not followed 
on fields next to the one that is infested.

The worms are overwintered larvae from the previous year. The adults are at 
large laying eggs in the summer, but other crops will deflect them. 
Soil-based pests are difficult to control organically, particularly in this 
setting. Beneficial nematodes, beneficial fungi, microbials, are used in the 
US and available here but export to Mexico can be difficult. The university 
in Colima and in Guadalajara may be one resource to investigate since they 
both have "sustainable" actives there with some familiarity with Organic.

Steve Sprinkel
Ojai Ecosystem Services