Last week I talked about pulling black plastic; that's about all done now. This week I'm going to be writing about managing organic matter (OM).
As we head into late fall, early winter I pause to give thoughts to how we can improve things for next year. One thing we'll do next year, and have done every year since time began, is to try to increase the organic matter in our fields. Organic matter management begins with a yearly soil test; we prefer to take ours in the fall as the lab has more time and we have ample time to plan for the coming season.
From the home gardeners' standpoint it's a pretty easy solution; add compost, leaves and/or peat moss and you have increased your level of organic matter. I add bedding from the henhouse, ashes from the furnace, leaves from the lawn and crop residues once harvesting has been completed. I've been known to pick up bags of leaves from the curb in local towns. Most anything that will break down in a year or so will do. I divide my garden into two plots; one for the garden next year and one I'll work on for the year after. The plot for next year will get the compost and the other plot will get everything else and a cover crop to boot.
When it comes to having acres and acres and you're trying not to break the budget too bad, well, that's a different story. Keeping up with the addition of organic matter on an acreage basis is more of a challenge; something you must think about as you plan your fields for the season. Growing a crop and plowing it under is often the most cost effective way of adding OM and nutrients on a large scale. If you're going to take a field out of production for a full season, you're going to want the most bang for your buck you can get; that's why it's important to manage it like any cash crop. Let's see: a one or two year crop that's going to add organic matter, bring nutrients up from deep in the soil, add nitrogen for the subsequent cash crop, compete with the weeds and be relatively easy to work with. And the answer is:
Hmmmmmmmmm. What a choice! Should I have two or three crops in one year, should there be one, should I plant a mixture; choices, choices. I need to plant something as early as the ground can be worked that will do everything I want it to do, that will be low maintenance and will perform well in almost any weather conditions that can and will happen. I need to make sure it can compete with early season weeds and grow vigorously throughout the growing season to make the most out of the one year it's going to get to grow unchecked. How much maintenance will it require? Will it perform better if it's mowed once or twice? So picking a cover crop to plant is more than just breezing through our selection and picking one out. It's determining what exactly I want to accomplish, how much time and money I want to invest and what my expected results are at the end of the season and for the next season.
Compared with all the variables, the money is the inexpensive part of the whole process. Anything you do will cost money. If your land stays fallow, it costs to keep the weeds from coming up, if you cover crop it; it costs in seed and expenses, if you seed it down for a couple of years it costs for seed and etc. And just taking it out of production for a year will cost money, so it's something to think about this winter and something to plan on for next spring.
So no matter what you do it's going to cost something. If you do nothing, that also costs as the ground will come up to weeds and become more of a problem down the line. Organic nitrogen is an added bonus if you're looking to add OM. Think about this for a second; once all that OM has been tilled in it's going to take some nitrogen to break it down so, unless you add some supplemental N, it's going to tie up what N you have in the soil breaking down all that carbon so we might as well add some N in the mix. Alas, where does this bring us to now? Picking a crop to seed and a timeline to do it: I think I'll use oats and clover or oats and annual alfalfa and seed it as early in the spring as I can get on the ground. The oats will be a nurse crop - to help the legume to get established. The red clover or alfalfa to add nitrogen, and the reason to plant it early - this mix likes cool weather, in fact it thrives in the cool, spring weather. Once thoroughly established it can take the heat and dryness of a typical Maine summer.
I'll probably wind up planting oats and red clover; it's one of my favorite mixtures. The oats will help the clover get established, the red clover will thrive just about anywhere; it will also vigorously regrow next spring and it will provide quite a lot of nitrogen to next year's crops. The only maintenance that this crop needs in a mowing once the oats reach maturity; this will kill the oats allowing the clover to come up now that it's established.
Until next week, Brian