Dry soil effect - 乾土効果

"Nature has so many things that she is trying to reveal, but we just don't know how to look at them..."  I don't remember where I heard this, but every time I am out observing natural environment and can't figure out what is going on, it pops up in my head.

Dry soil - first thing that comes to most minds are when soil goes dry, you have to irrigate.  Dry soil is generally considered not productive in farming.  It's true in common organic and conventional farming practice, but natural farming takes it quite differently

In natural farming dry soil is natural consequence of seasonal changes.  There are wet season and dry season.  There are many plants naturally adapt the changes, but our vegetables and flowers cannot adapt this!?  Isn't there something wrong with us?

I found this dry soil effect as part of fertilizer poisoning.  There was a seed germination experiment of brassica with moisture and fertilizer application and concentration of N level.

A1 - control No N fertlizer Moisure low Germination success - high	A2 N fertilizer applied Moisture low Germination success - Low
B1 No N fertilizer Moisture high Germination success - Mid	B2 N fertilizer applied Moisture high Germination success - high

A1 is no fertilizer applied and moisture is kept moist but low, just enough for the seeds to germinate.  This is similar to natural farming condition.

What's so great about this experiment is A2 and B2 tell us when N fertilizer is applied or high concentration of N is present in the soil, germination is greatly affected by moisture level.  This is also sometimes referred to as fertilizer burn or nitrogen burn.

Nitrogen and Moisture

Since nitrogen is highly soluble in water, concentration of nitrogen is highly affected by moisture level.  This is why in fertilizer based farming both chemical based and organic requires irrigation in dry period.  While natural farming actually improves growth when soil start to dry.  

I have repeatedly experienced that plant growth suddenly improves when the soil start to dry when there is no fertilizer applied.  Occasionally, there is residual fertilizer effect, but in natural farming when fertilizer is entirely cleaned out of the soil, it is said that the soil naturally create what is needed for plant growth.  

Some researchers in Japan showed that available soil nutrient is generally not enough for plants to grow, but natural farming vegetables grow with such vigor that it is often confused with fertilizer effect.  

Soil is much more than what nutrients are available to grow plants, but there are lots of microbial activities as well as yet unknown phenomena.  First thing I notice when fertilizer is removed from soil is that certain types of microorganisms like mushrooms become more dominant.  Not all kinds of mushrooms, but typically mushrooms are the ones that rely on carbon or lignin as source of foods.  In natural world, there is nothing that applies so much fertilizer like we human do.  Most cases here and there with bird droppings and so on, and most plants takes out nitrogen before they die in form of seeds or spores, and dispersed.  

I noticed our native Hawaiian Ohia trees and grasses continuously dropping leaves to create constant cycling. Typically grasses and leaves that fall on the ground are hard, brown, and high carbon materials.  Natural environment keeps high carbon environment.  They naturally cumulate carbon.  Soil builds more carbon and humus.  Fertilizer burns carbon out of soil.  If we work with nature, carbon is a part of solution and shouldn't be a problem.

Many things in nature are great at dispersing potentially harmful concentration effect.  Pest and disease are part of this natural mechanisms of dispersion.  We should be grateful that they are telling us that those vegetables that attract pests and disease have problems.

What I want to say is that dry soil shouldn't be a problem, but is a way for us to see how nature deals with seasonal changes and correct our behavior to respect and work with nature.  Working with nature requires least work and most sustainable way of farming since nature is self-sustaining.

"Nature has so many things that she is trying to reveal, but we just don't know how to look at them..."
We just have to shed biases and look through pure minds.