I have a very successfully 4 acre plot that’s been divided 1/2 with perennial clover and the other half brassicas via throw n mow/spray. Last year I decided to rotate as the brassicas have been in the same portion for 3 years and the clover side was getting overtaken with grass. I did everything like I usually do - spread seed, spray, mow a week later. This led to very few brassica coming up and mostly grass. I decided to burn everything down again and spread brassica, again very little came up as it was overtaken with grass. Why am I doing wrong on this side of thee plot?