I have never grown a green manure before and am not clear, from what I have read, as to how exactly I should dig in the crop before it reaches flowering time.
Does 'digging in' simply mean turning the soil over with a fork to incorporate as much as possible of the top-growth into the top 4 to 6 inches? If I do that, won't it continue growing and sprout up again?
Or do I use a spade and start trenching and totally bury the growth from one trench-line into the bottom of the previous trench-line? - sort of like double digging. If so, that does sound like a lot of work.
Just turn it under, a spading fork is fine. If it sprouts and regrows turn it under again. Which crop are you using for green manure? Because you just might have time for a second or third sowing before winter. For example if you are turning under clover or beans now you could sow buckwheat and turn that under and then sow winter rye.
IF you dig, do it about three weeks before you plan to plant.
IF you're going to dig, work it into the top 8" - 24" of soil.
IF you are going to dig, this is a good method to do ONCE but not necessary.
My preferred method is to cut it and leave it lie. Then mulch over the cut plants. Wait two to three weeks and plant. This is a very modified form of lasagna gardening and it is a no dig approach to gardening. If you are worried about reemergence of the "green manure" or weeds, layer black and white news print over your planting area. If your soil is very hard and compact you may want to digthe "green manure" in the first time (I'd use a garden fork to reduce damage to the worms) or use some buckwheat or rye in combination with a nitrogen fixing plant like beans, or peas, or clover, or alfalfa.
Rye and buckwheat can put an incredible amount of organic material into the soil as roots. Every year will just get better ;O)
I think you probably need to grind the cover crop and dig into the soil so that it could decompose more quickly. Infact if organic matter decompose too slowly, it can activate anaerobic processes in the soil that could impair the following crop. In such way you increase the content in organic matter. Another thing you need to be carefull to is the C/N ratio: if the organic matter N content is not enough, the same organic matter can reduce the N content in the soil little by little during the humification process. At a same time you must consider that cover crop and green manure is often practiced during wintertime, a season in which rain usually wash away many mineral elements from the soil, so that green manuring during this season is anyway a good practice to prevent this loss of nutrient elements from the soil. I hope this could help,
All that stuff you say about C/N ratios just drives me crazy, I don't understand a word of it.
Me, I have a lot of ground that will be spare over the winter. I just want to know how to go about simply sowing green manure and digging it in afterwards.
But you're making it sound too complex for me , ,,,,,,,,,,,maybe I just leave the soil bare.
You can use different green manures: the better you can use are fodder crops (Leguminous plants): they will cover the soil during the fall (autumn) (-> cover-crops) and prevent the washing away of nutrientsand soil erosion. Before the crop will flower you need to mow, grind an dig it in the soil so that it could decompose little by little. This green manure will increase the content of organic matter and also the N content because leguminous plants store high levels of nitrogenum in their tissues. When they decompose they generate a humus with low C/N (very good is C/N = 10) ratio. If you, on the contrary, use, for example, the wheat straw, you will have a compost with high C/N ratio. This fact will cause humus balance its N content taking it from the soil so that the plants, next, will probably suffer from N hunger.
So mow it, grind it and dig it not too deep in the soil, because in that case, if the soil clay content is very high (as frequently happens in certain places), you will risk the manure fermentate and generate toxic compounds. Infact the organic matter needs oxygen during is composting to generate a good compost/humus.
If it is Winter Rye mowed after about April 15 (Zone 6) it will all be dead as a door nail in about 3 days. If the sun is shining, there won't be any traces of green. The stubble will look like wheat straw.
When planting, I've read that you should plant the seed under 1 1/2 times its' diameter in dirt. With that in mind I would use small seeds to reduce the work (clover, rye, buckwheat, ect.) On the other hand, if your field needs to be mowed, cast your seeds just after cutting it. If it doesn't need to be mowed, you could mulch it, and then sow your seeds. Last year, I just cast mine into the mulch, and it worked. Nature doesn't dig her seeds in ;O)
I couldn't tell you but I'll never grow green cover crops again. I switched to sheet composting with shredded yard and garden waste and piles of leaves. All are turned under in early spring with fertilizer and the gardens tilled a few times before being planted. First in are the lettuce, collards and beets.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.