# Soil Test Question/Help



## lrw_3 (May 9, 2018)

Why does my soil vary so much in PH front vs back? Is this common? 
The house was built in 2009 and I believe that the front yard has a lot of fill from building the pad that the house is on and the backyard is more native soil.

As far as their recommended amendments. I understand the lime in the front yard.

I dont understand the NPK recommendations. Sorry for the newb questions just curious on how to properly interpret the tests

TIA


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## Suburban Jungle Life (Mar 1, 2018)

Which grass type are you growing? You put centipede in your bio but then they list bermuda and st. augustine. The PH for centipide is lower than the others.


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## lrw_3 (May 9, 2018)

Suburban Jungle Life said:


> Which grass type are you growing? You put centipede in your bio but then they list bermuda and st. augustine. The PH for centipide is lower than the others.


Thanks for pointing that out lol. I need to update that cause some things have changed. I thought I had centipede in the front and I definitely had centipede in the back. Turns out I had Centipede/St Augustine in the the front. Since joining the forum I started renovating the backyard with Bermuda which is an on going project.

In the front I would like to encourage the st aug to grow since i think it is a better grass than the centipede so that is why I put St aug for the front grass.

In the back i would like to have bermuda where it will grow and centipede in the shady spots. This may look funny but I may try to replace the centipede with some shade tolerant zoysia down the road in the back. Its kind of a frankenlawn right now but I have to start somewhere. I have a decent size lawn so its not feasible for me to fix it all at once and its a mix of sun and shade with a lot of dog and kid traffic.


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## Ridgerunner (May 16, 2017)

> Why does my soil vary so much in PH front vs back? Is this common?
> The house was built in 2009 and I believe that the front yard has a lot of fill from building the pad that the house is on and the backyard is more native soil.
> 
> As far as their recommended amendments. I understand the lime in the front yard.
> ...


I wouldn't say the difference in pH of >1 is common, but it's certainly not shocking as there are a number of common conditions that could account for it. For instance, it's not unusual for front lawns get more fertilizer and watering than back lawns and both can increase acidity. If your front lawn had a pH of <5 and your back lawn had a pH >8, that would be unusual.
The NPK recommendations are for the entire growing season. The rule of thumb is to not apply more than:
1. one pound of Nitrogen per thousand square feet per month. For instance they suggest 14.4 pounds of ammonium sulfate/M. Ammonium sulfate is 21% N, so 14.4 X .21 = 3.02 pounds of N/M. That would be 3 separate applications of 1#N/M or 4.8 lbs of ammonium sulfate product per thousand square feet in any one month. Same method of calculation for urea which is 46% N and ammonium nitrate which is 34% N.
2. one pound of P2O5 /M in any one month. Triple supper phosphate is 45% P2O5, so you could apply up to 2 lbs/M of triple supper phosphate in a one month period although I would suggest no more than one pound of super triple phosphate in any one month period. They recommend 1.5 lbs/M of STP, although you could apply that whole amount at one time, I'd make three applications of 0.5 lbs/M over the rest of the season (each separated by at least one month.
3. one pound of K2O /M in a one month period. They recommend 2.3 lbs /M of muriate of potash. MOP is 60% K2O. I'd suggest you use Sulfate of potash (SOP) as plants don't need the extra chloride from the MOP, but can use the sulfate from the SOP, plus SOP has a lower salt index than MOP and is less harsh to the turf. SOP is 50% K2O. 2.3 lbs of MOP is 1.38 lbs of K20, so make two apps of 1.15 lbs of MOP product /M no sooner than one month apart.
Does that help you understand the recs or was there something else?

Finally, don't do anything until viva gets back to you. The recommendations are for St A and Bermuda, not Centipede. You're going to need adjustments.


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## lrw_3 (May 9, 2018)

@Ridgerunner thanks for the information. That covers most of my questions. I was unsure how much I could add at one time and you cleared that up. I have a Chaplin backpack sprayer would it be easier for me spray the SOP or does that get tricky? I've never sprayed any fertilizer but would like to get there one day. All my fertilizer have been applied granularly. Is there a how to thread that covers liquid fertization? I read mightquin's thread on his liquid program but it doesn't really clear up how much carrier water to product ratio to use and wether or not it needs to be watered in immediately. Anyways that will be down the road for me probably as I read more and gather more information. Thanks for your help!


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## Ridgerunner (May 16, 2017)

@lrw_3 The recommendations nutrient additions are intended to adjust the soil levels. Generally, the purpose is to reach levels sufficient to supply the turf with a year's worth of nutrients from the soil though the roots. Spray/foliar application is intended to to supply the turf with short term nutrients through leaf absorption and amounts applied should be regulated so as not to cause damage to the plant. It would be possible to apply nutrients to the soil with proper nozzles and immediately washing the plant leaf to get the nutrients to and in the soil. Although that is a practical method for applying micro-nutrients (due to the small application quantities), the effort and care needed to do that for the quantities of the major soil based nutrients needed would be immense. I believe @Ware has done micro-nutrient spray apps for soil adjustment, but @Mightyquinn would likely be the one for advice on spay application of major nutrients, I don't know if he would have any experience with that method for adjusting soil levels or not, but he'd be the one if you are just interested in developing a straight foliar fertilizing regiment.


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## lrw_3 (May 9, 2018)

I will am going to adjust my soil using the normal method with granules. The liquid application was just a thought. I appreciate all your help and suggestoins @Ridgerunner


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