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ParadiseLS
06-02-2011, 12:26 AM
I've been thinking a lot about SOM/compost as it relates to my apps of different OTC organic products that control weeds and bugs.

1. corn gluten. I've felt pretty good about applying CGM to most of my customers' lawns because of heavy clay, low SOM content, and history of heavy chemical usage. I figure, the microbial activity is far from ideal on these lawns and as such, the CGM will have a longer period of effective weed suppression. Also, because the N content of the CGM is so high, I figure a longer period of breakdown helps keep a steadier, lower addition of N than if the microbial activity were breaking down the CGM faster. This is good because a) i don't want the lawns growing like crazy, just steadily, and b) although N isn't as important as P, high additions will negatively effect any mycchorizae that are spreading about the soil in search of nutrients to mine.

2. iron/fiesta. I'm wondering what effect a raise in SOM would have on the efficacy of weed control products that are iron-based. Would the OM help insulate the grass so that it would not be effected as much by the app? would it significantly improve the weeds' chances of surviving an application, forcing me to spray an extra application every time?

3. Nematodes. Is it even really worthwhile to spray nematodes into a cruddy clay soil to go after the grubs? How well do nematodes last in clay, low som soils? what kind of improvement in efficacy would i expect to find if i raised SOM% by 2-3 points, say from 6% to 8%? and obviously, it seems to me that if you really raise the SOM% than you produce an evironment where after you introduce the beneficial nematodes, they are more likely not only to have a stronger attack on the grubs from one app, but more likely to stick around and reduce or eliminate the need for their use in the future....

ICT Bill
06-02-2011, 09:49 AM
I've been thinking a lot about SOM/compost as it relates to my apps of different OTC organic products that control weeds and bugs.

1. corn gluten. I've felt pretty good about applying CGM to most of my customers' lawns because of heavy clay, low SOM content, and history of heavy chemical usage. I figure, the microbial activity is far from ideal on these lawns and as such, the CGM will have a longer period of effective weed suppression. Also, because the N content of the CGM is so high, I figure a longer period of breakdown helps keep a steadier, lower addition of N than if the microbial activity were breaking down the CGM faster. This is good because a) i don't want the lawns growing like crazy, just steadily, and b) although N isn't as important as P, high additions will negatively effect any mycchorizae that are spreading about the soil in search of nutrients to mine.

2. iron/fiesta. I'm wondering what effect a raise in SOM would have on the efficacy of weed control products that are iron-based. Would the OM help insulate the grass so that it would not be effected as much by the app? would it significantly improve the weeds' chances of surviving an application, forcing me to spray an extra application every time?

3. Nematodes. Is it even really worthwhile to spray nematodes into a cruddy clay soil to go after the grubs? How well do nematodes last in clay, low som soils? what kind of improvement in efficacy would i expect to find if i raised SOM% by 2-3 points, say from 6% to 8%? and obviously, it seems to me that if you really raise the SOM% than you produce an evironment where after you introduce the beneficial nematodes, they are more likely not only to have a stronger attack on the grubs from one app, but more likely to stick around and reduce or eliminate the need for their use in the future....

clay soils (not all) typically have low SOM content especially if compacted. my experience has been to start a tea program the SOM has to be 2% minimum we would like to see it between 5% and 7% ideally, if you have 6 to 8 you are good shape generally

I have no experience with fiesta so I can't help you with that

Nematodes need a moist soil, if it is too dry or compacted they are a waste of time, timing is also critical, many put them down way to early in the season they should be applied at the first instar stage

phasthound
06-02-2011, 05:39 PM
iron/fiesta. I'm wondering what effect a raise in SOM would have on the efficacy of weed control products that are iron-based. Would the OM help insulate the grass so that it would not be effected as much by the app? would it significantly improve the weeds' chances of surviving an application, forcing me to spray an extra application every time?

From Engage Agro;
The FE in Fiesta functions as a catalyst for oxygen reduction, which causes the production of unstable and highly reactive oxygen radicals, such as hydroxyl radicals, which in turn cause cellular damage within the plant. The excessive uptake of FeHEDTA by many broadleaved species leads to tissue necrosis and ultimately death of the weed. Broadleaf weed are generally more susceptible to the herbicidal effects of FeHEDTA than are grass species. The mechanism of selectivity is not entirely understood but is believed to relate in part to differences in uptake of FeHEDTA perhaps related to physiological tolerance and reasons related to plant morphology; angle of the leaf blade causing runoff, etc.

I don't think SOM would have much effect on Fiesta's efficacy. Since it's introduction to the USA this year, I've spoken to several organic landscape companies who have reported very good results with Fiesta where they have high SOM.