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Post by MoBuckChaser on Jun 1, 2017 9:28:48 GMT -6
Some of my Sand farmers see a real response when using Ammonium Sulfate when farming blow sand. You may want to look into that jerry. Does much sulfur come from manure and if so, which kinds of manure? I need to ask some of my farmers this question.  |
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Post by sd51555 on Jun 1, 2017 11:23:52 GMT -6
If I were staring at 6 acres of by-hand follow up N application, I'd do a soil test. The debate rages on when it comes to the N credit from legumes. Some say zero, some say "x". I'm convinced there is no hard and fast rule. The Hefty guys talk about doing a pre-sidedress nitrate soil test. It's not a full blown soil test. However, if you don't have one, I'd get one. In this case, knowing your organic matter will help. Working backwards from that soil test, you'll know how much nitrogen you have to start, plus you can count ~25lbs/N/ac for every 1% organic matter you have. If you're shooting to put on 150 lbs for the season, you may only need 60, split it into two applications. Might save you a lot of time, money, and sweating. Help me with some math here. I have organic matter of 1.5%, which would tell me my soil can only hold 37.5 Lbs. of actual Nitrogen. If my goal is 150 Lbs. of actual nitrogen I would need more than 2 applications to get effective use of the nitrogen.
Fertilizing Actual
Step Nitrogen Comment
N-Credit 20.0 Prior Year Soybeans
Pre-plant 40.5 Tilled into Ground
Side Dress ?? All at once or 2-3 broadcast (need 90 Lbs. actual Nitrogen)
Total Nitrogen 150 Lbs.
I could probably get by with two final side dress applications of 45 Lbs. each. I'm thinking I could apply my second application around week 6-7 Post-plant. Can I drive over corn after 6 weeks and have it still rebound? If I could it would leave me with only one hand broadcast.
FB
Organic matter doesn't tell you how much you can hold, it tells you how much you're going to get for free from your soil (organic matter x 25). CEC from your soil test will tell you what you can hold. If you don't have that, you're still not completely out of luck. If you're sandy, I'd safely assume you can hold about 70lbs N, unless you're on the type of sand that you can drive on an hour after a rain with no consequence. With your numbers above, you'll have: 20 lbs soybean credit 37.5 lbs from OM 40.5 pre-plant
98 lbs on already. 50 more at one sidedress application, and you're good to go. |
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Post by Freeborn on Jun 1, 2017 11:35:19 GMT -6
Help me with some math here. I have organic matter of 1.5%, which would tell me my soil can only hold 37.5 Lbs. of actual Nitrogen. If my goal is 150 Lbs. of actual nitrogen I would need more than 2 applications to get effective use of the nitrogen.
Fertilizing Actual
Step Nitrogen Comment
N-Credit 20.0 Prior Year Soybeans
Pre-plant 40.5 Tilled into Ground
Side Dress ?? All at once or 2-3 broadcast (need 90 Lbs. actual Nitrogen)
Total Nitrogen 150 Lbs.
I could probably get by with two final side dress applications of 45 Lbs. each. I'm thinking I could apply my second application around week 6-7 Post-plant. Can I drive over corn after 6 weeks and have it still rebound? If I could it would leave me with only one hand broadcast.
FB
Organic matter doesn't tell you how much you can hold, it tells you how much you're going to get for free from your soil (organic matter x 25). CEC from your soil test will tell you what you can hold. If you don't have that, you're still not completely out of luck. If you're sandy, I'd safely assume you can hold about 70lbs N, unless you're on the type of sand that you can drive on an hour after a rain with no consequence. With your numbers above, you'll have: 20 lbs soybean credit 37.5 lbs from OM 40.5 pre-plant
98 lbs on already. 50 more at one sidedress application, and you're good to go. I see, thanks for the help with the math.
FB
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Post by Freeborn on Jun 1, 2017 11:40:00 GMT -6
Follow-up to all of this, why do we only test the top 6" of soil when plant roots are often much deeper? Does the top 6 Inches match the profile of deeper soils?
For food plotting it probably doesn't matter but it seems for Ag production you would want deeper soil samples.
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