I came across a great website yesterday, it contains a online version of a good book about growing vegetables with very little irrigation by a author I have read and respected for many years. He has given growers the permission to use this online version.
Originally this book was meant for gardeners living between the Pacific ocean and the Cascade mountains in Northern California,western Oregon, western Washington, and SW Brittish Columbia, a region with great summer conditions for growing, but with very little rainfall. He says that even though this book was written for the PacNW, that the content could be usefull for people all over the USA, or the world for that matter, and I agree.
This book is written for vegtable gardening, but most of the basics apply for growing any usefull plants.
This book provides lots of good info about figuring out your water needs, estimating how well the rain is watering, and showing you how much water your soil can hold. Check it out-
Gardening Without Irrigation: or without much, anyway, by Steve Solomon
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I'm going to post a few quotes from the book, just to give a example of whats inside-
From the preface-
"Sasquatch Books is a quality west coast publisher specializing in regional books. Their Cascadia Gardening Series is a group of inexpensive, topic-specific books intended for distribution only along the Pacific slope of Washington, Oregon and Northern California, and in the Lower Mainland and Islands of British Columbia. Most of the series covers subjects like "Regional Roses."
My book, Gardening Without Irrigation, never quite fit into that series because the techniques it explains apply everywhere a food grower is faced with the possibility--or actuality--of not having irrigation or not having enough irrigation.
Gardening Without Irrigation can help anyone whose garden depends on a limited or undependable well, anyone who gardens on natural rainfall, for any place faced with the possibility of drought."
From chapter 1
"Defined scientifically, drought is not lack of rain. It is a dry soil condition in which plant growth slows or stops and plant survival may be threatened. The earth loses water when wind blows, when sun shines, when air temperature is high, and when humidity is low. Of all these factors, air temperature most affects soil moisture loss."
"The kind of vegetation growing on a particular plot and its density have even more to do with soil moisture loss than temperature or humidity or wind speed. And, surprising as it might seem, bare soil may not lose much moisture at all. I now know it is next to impossible to anticipate moisture loss from soil without first specifying the vegetation there. Evaporation from a large body of water, however, is mainly determined by weather, so reservoir evaporation measurements serve as a rough gauge of anticipated soil moisture loss."
From chapter 2
"Soil is capable of holding on to quite a bit of water, mostly by adhesion. For example, I'm sure that at one time or another you have picked up a wet stone from a river or by the sea. A thin film of water clings to its surface. This is adhesion. The more surface area there is, the greater the amount of moisture that can be held by adhesion. If we crushed that stone into dust, we would greatly increase the amount of water that could adhere to the original material. Clay particles, it should be noted, are so small that clay's ability to hold water is not as great as its mathematically computed surface area would indicate."
From chapter 7
"When using any type of drip system it is especially important to relate the amount of water applied to the depth of the soil to the crops, root development. There's no sense adding more water than the earth can hold. Calculating the optimum amount of water to apply from a drip system requires applying substantial, practical intelligence to evaluating the following factors: soil water-holding capacity and accessible depth; how deep the root systems have developed; how broadly the water spreads out below each emitter (dispersion); rate of loss due to transpiration. All but one of these factors--dispersion--are adequately discussed elsewhere in Gardening Without Irrigation.
A drip emitter on sandy soil moistens the earth nearly straight down with little lateral dispersion; 1 foot below the surface the wet area might only be 1 foot in diameter. Conversely, when you drip moisture into a clay soil, though the surface may seem dry, 18 inches away from the emitter and just 3 inches down the earth may become saturated with water, while a few inches deeper, significant dispersion may reach out nearly 24 inches. On sandy soil, emitters on 12-inch centers are hardly close enough together, while on clay, 30- or even 36-inch centers are sufficient.
Another important bit of data to enter into your arithmetic: 1 cubic foot of water equals about 5 gallons. A 12-inch-diameter circle equals 0.75 square feet (A = Pi x Radius squared), so 1 cubic foot of water (5 gallons) dispersed from a single emitter will add roughly 16 inches of moisture to sandy soil, greatly overwatering a medium that can hold only an inch or so of available water per foot. On heavy clay, a single emitter may wet a 4-foot-diameter circle, on loams, anywhere in between, 5 gallons will cover a 4-foot-diameter circle about 1 inch deep. So on deep, clay soil, 10 or even 15 gallons per application may be in order. What is the texture of your soil, its water-holding capacity, and the dispersion of a drip into it? Probably, it is somewhere in between sand and clay."
The last few chapters deals with vegetables mostly, but I think there is lots of good info for guerrilla Cannabis growers who have concerns about water for their plants.
I'll be happy to discuss this with any who are interested, and I'll be writting more concerning this book, and the info it contains.
Originally this book was meant for gardeners living between the Pacific ocean and the Cascade mountains in Northern California,western Oregon, western Washington, and SW Brittish Columbia, a region with great summer conditions for growing, but with very little rainfall. He says that even though this book was written for the PacNW, that the content could be usefull for people all over the USA, or the world for that matter, and I agree.
This book is written for vegtable gardening, but most of the basics apply for growing any usefull plants.
This book provides lots of good info about figuring out your water needs, estimating how well the rain is watering, and showing you how much water your soil can hold. Check it out-
Gardening Without Irrigation: or without much, anyway, by Steve Solomon
---------------------------------------------------------------------------------------------
I'm going to post a few quotes from the book, just to give a example of whats inside-
From the preface-
"Sasquatch Books is a quality west coast publisher specializing in regional books. Their Cascadia Gardening Series is a group of inexpensive, topic-specific books intended for distribution only along the Pacific slope of Washington, Oregon and Northern California, and in the Lower Mainland and Islands of British Columbia. Most of the series covers subjects like "Regional Roses."
My book, Gardening Without Irrigation, never quite fit into that series because the techniques it explains apply everywhere a food grower is faced with the possibility--or actuality--of not having irrigation or not having enough irrigation.
Gardening Without Irrigation can help anyone whose garden depends on a limited or undependable well, anyone who gardens on natural rainfall, for any place faced with the possibility of drought."
From chapter 1
"Defined scientifically, drought is not lack of rain. It is a dry soil condition in which plant growth slows or stops and plant survival may be threatened. The earth loses water when wind blows, when sun shines, when air temperature is high, and when humidity is low. Of all these factors, air temperature most affects soil moisture loss."
"The kind of vegetation growing on a particular plot and its density have even more to do with soil moisture loss than temperature or humidity or wind speed. And, surprising as it might seem, bare soil may not lose much moisture at all. I now know it is next to impossible to anticipate moisture loss from soil without first specifying the vegetation there. Evaporation from a large body of water, however, is mainly determined by weather, so reservoir evaporation measurements serve as a rough gauge of anticipated soil moisture loss."
From chapter 2
"Soil is capable of holding on to quite a bit of water, mostly by adhesion. For example, I'm sure that at one time or another you have picked up a wet stone from a river or by the sea. A thin film of water clings to its surface. This is adhesion. The more surface area there is, the greater the amount of moisture that can be held by adhesion. If we crushed that stone into dust, we would greatly increase the amount of water that could adhere to the original material. Clay particles, it should be noted, are so small that clay's ability to hold water is not as great as its mathematically computed surface area would indicate."
From chapter 7
"When using any type of drip system it is especially important to relate the amount of water applied to the depth of the soil to the crops, root development. There's no sense adding more water than the earth can hold. Calculating the optimum amount of water to apply from a drip system requires applying substantial, practical intelligence to evaluating the following factors: soil water-holding capacity and accessible depth; how deep the root systems have developed; how broadly the water spreads out below each emitter (dispersion); rate of loss due to transpiration. All but one of these factors--dispersion--are adequately discussed elsewhere in Gardening Without Irrigation.
A drip emitter on sandy soil moistens the earth nearly straight down with little lateral dispersion; 1 foot below the surface the wet area might only be 1 foot in diameter. Conversely, when you drip moisture into a clay soil, though the surface may seem dry, 18 inches away from the emitter and just 3 inches down the earth may become saturated with water, while a few inches deeper, significant dispersion may reach out nearly 24 inches. On sandy soil, emitters on 12-inch centers are hardly close enough together, while on clay, 30- or even 36-inch centers are sufficient.
Another important bit of data to enter into your arithmetic: 1 cubic foot of water equals about 5 gallons. A 12-inch-diameter circle equals 0.75 square feet (A = Pi x Radius squared), so 1 cubic foot of water (5 gallons) dispersed from a single emitter will add roughly 16 inches of moisture to sandy soil, greatly overwatering a medium that can hold only an inch or so of available water per foot. On heavy clay, a single emitter may wet a 4-foot-diameter circle, on loams, anywhere in between, 5 gallons will cover a 4-foot-diameter circle about 1 inch deep. So on deep, clay soil, 10 or even 15 gallons per application may be in order. What is the texture of your soil, its water-holding capacity, and the dispersion of a drip into it? Probably, it is somewhere in between sand and clay."
The last few chapters deals with vegetables mostly, but I think there is lots of good info for guerrilla Cannabis growers who have concerns about water for their plants.
I'll be happy to discuss this with any who are interested, and I'll be writting more concerning this book, and the info it contains.
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