Very disappointed in my throw and mow results. The buckwheat was sparse, the lablab mix was even worse. Imma blame it on the weather and maybe not enough thatch to help the germination. The soil is a heavy clay, well drained to considerably moist. At best, i have about 5% germination. Big waste of money for me.
I see this all the time. I have heavy clay. Understanding your soils, what is wrong, and how they respond is critical. While weather can always be a problem, there are other issues with heavy clay.
First, I ruined many of my early plots by using a 2-bottom plow and turning the soil. You've probably watched the "Ray the soil guy" videos which is why you are using T&M. I destroyed the soil tilth and lost what little OM I had with deep tillage. My original method was to use a 2-bottom plow followed by a tiller for a nice fluffy seed bed. Probably the worst think I could have done for my soil.
When I started T&M, it was a bust. Winter Rye was sparse and other crops were a bust. I drilled soybeans for summer and even they had issues. Why?
With low OM and no microbiology in the soils to speak of, clay will form a hard crust. Rain won't penetrate much at all. It tends to run off. Ray's infiltration video is a great demo. Drilled soybeans had a hard time breaking through the crust some years. It just depended on how much rain, how hard it rained, and when.
Keep in mind, building OM and restoring soil health takes decades, not a couple years. You build OM from the top down. The answer for me was Min-till. I accomplished it with a 3-pt tiller. I raised it so high, that the tines don't hit more than the top inch of soil. It disturbs the vegetation and kicks a small amount of dirt. This helps the vegetation decompose a bit faster, but more importantly, it breaks up that hard crust in the clay. When I'm done min-tilling a field, the field is still green with a slight tint of brown when you look at it from a distance. You would think it had been mowed, not tilled. I then broadcast, cultipack and spray.
Using a cultipacker becomes important in the clay. Not only does it press the seed into the ground and remove air pockets, it creates an uneven surface (dimples or troughs) that helps keep the water from running off when it rains. Never let your soil go bare. The lack of vegetation on the soil promotes crusting.
The next step is to make deer secondary, and soil health primary. There are plenty of crops that promote soil health that are great deer food, so you don't really need to sacrifice anything. The primary purpose is to build OM. Choose crops in ratio that have a good C:N ratio for building OM. Basically it is a mix of grasses and legumes that produce biomass. I plant both spring and fall. Over time, I built some OM, so I get much less crusting. I can T&M now most of the time, but I still check the soil for crusting and min-till when necessary. Last year I tried a very light disc and it seemed to be shallow enough for min-till. I made just one fast pass.
I'm now to the point where I've stopped fertilizing. I've got nutrient cycling working in my soil. It has be several years since I fertilized and I've noticed no change in crops or deer use. I'm not saying that I'll never need to fertilize again and I do soil tests every few years, but a smart selection of low fertility requirement crops and better nutrient cycling has dramatically reduced my planting cost.
On the upside for heavy clay, lime moves very slowly thorough it. This means you need to be patient with the initial application for it to reach root depth. I only top dress lime and never till it in as tillage was the start of many of my problems. My soil takes about 4 tons/ac of ag lime to amend it and they suggest only applying 3 tons in a single application. It takes 3 to 5 years before the pH drops enough for 1 ton/ac of maintenance lime after that because it moves so slowly. So, be thankful you have heavy clay. It is better than sand on the other end of the spectrum, but we all envy those guys in big ag country with fertile loam. Those fertile soils can take much more abuse from tillage and recover than my marginal soils.
Hope this helps you stay the course...
Thanks,
Jack