Science Forums 2

[maikeru]

Originally Posted by nutronjon

Okay, we must work with both chemistry and biology to get a tangible grip on what is life. May be with a focus on tangible reality, this thread will be managable?

I believe I killed many seeds, by trying to rush sprouting. I soaked them in water and then let them dry out, because I decided the seeds where too small to sprout that way. Now they are planted in soil and won't sprout. Conclusion I killed them, and this must have something to do hydrogen. Right?

No worries, hydrogen should have little to do with untimely seed death.

There are several ways to rush sprouting. UncleAl, as usual, gives awesome tips. I always learn a lot from his posts. Here are two tips I find useful:

1. Humidity chamber: A moist, warm chamber where you can sprout seeds. Bottom of container can have something like soil, fine gravel, charcoal, or sand to an absorbent material like cotton. Try to keep it clean or sterile. If it is too dirty or too hot, bacteria and fungi can grow and rot your seeds. Many humidity chambers also contain a container or cup of water in the center to provide adequate humidity. E.g., a red clay pot filled with water with gravel around it in the chamber works quite well. The chamber should have a lid or top on it, so that it does not dry out and makes for easy seedling removal or cleaning.

2. Light and heat. This depends on the type of seeds you're trying to sprout, but I find many plant seedlings like a bit of heat. If you can keep them incubated at around 20-30 C continually, you can get them to sprout in half the time they normally would...or possibly faster. The hotter it is, the faster they sprout. You can also place your humidity chamber or a cellophane-topped pot with the seeds in weak to moderate sunlight, provided the temperature doesn't reach like 35-40 C and fry the seeds. Many seedlings do not sprout quickly without light. Some require weak light and others like strong light. This is also influenced by how deep you bury seeds and what "soil" the seeds are sprouting in. If you have them in cotton or tissue paper, then they will receive quite a lot of light with little trouble.

Some of my soil is very woody, and this depletes nitrogen, which is need for growing plants. Right? What is happening here? Why would wood deplete nitrogen and why must plants have it?

Soil microbes like bacteria and fungi are trying to digest the cellulose and lignans in the wood buried in the soil. Wood is mostly composed of C, H, and O, and very little N as I recall. In order to digest the wood, the microbes have to produce enzymes and multiply exceedingly, which means they suck up any available nitrogen. It's a matter of food, reproduction, and survival for them. Plants also need nitrogen to produce amino acids and proteins, etc., so they find themselves competing with the soil microbes when there's something like wood, coffee grounds, or charcoal in the soil. Coffee grounds and charcoal, it seems, act like filters/sponges and suck up nutrients from the surrounding soil, which also can create a low-N situation. (This is remedied either when the coffee grounds decompose and their organic acids breakdown or are leeched or you "dope" the grounds and charcoal with more N from say a source like a chemical or organic fertilizer rich in N.)

Be aware that some plants require more N than others, and it also depends on what they are doing. Generally an abundance of nitrogen supports the growth of more leaves and stems. If you want them to produce flowers or fruits, I believe potassium is the key.

Next question, why is it so easy to kill the plants we want, and so hard to get rid of the plants we don't want? Seriously- may be understanding this, will improve my ability to get desired results.

I discovered much of the ease in gardening comes from making the soil better and healthier. Whether it is in a pot or out in the yard, healthier, nutrient-rich soil supports healthier and bigger plants. Healthier, bigger plants also crowd out and compete against weeds more effectively, because weeds are often adapted to growing well in poor soils. Feed the soil and your plants will take care of themselves quite well, against bugs, bad weather, or excessive harvesting and cutting. Let me put in a plug for terra preta here.

Try to take care of soil microbes and soil animals like beetles, soil mites, earthworms, etc. Feed them with things like compost, leaf litter, etc. These critters help to digest refuse and create soil organic matter (e.g., worm castings). And they help to provide aeration for soil microbes that might be involved in nitrogen fixing or decomposition. In the presence of oxygen, things decompose more quickly. Without enough oxygen or air circulating in the soil, aerobes and plant roots suffer and can die or rot. With aeration, you'll be surprised how much better plants do. Extra aeration can be provided with more humus/organic matter in the soil, which causes clumping of the soil into soft aggregates, charcoal chunks, bark, mulch, gravel, etc. Softer, workable soil also allows you to pull out weeds and unwanted plants with ease.