[ Pobierz całość w formacie PDF ]
//-->Cascadia Gardening SeriesGardening Without Irrigation:or without much, anywaySteve SolomonIntroductionStarting a New Gardening EraFirst, you should know why a maritime Northwest raised-bed gardenernamed Steve Solomon became worried about his dependence onirrigation.I'm from Michigan. I moved to Lorane, Oregon, in April 1978 andhomesteaded on 5 acres in what I thought at the time was a cool,showery green valley of liquid sunshine and rainbows. I intended toput in a big garden and grow as much of my own food as possible.Two months later, in June, just as my garden began needing water, myso-called 15-gallon-per-minute well began to falter, yielding lessand less with each passing week. By August it delivered about 3gallons per minute. Fortunately, I wasn't faced with a completelydry well or one that had shrunk to below 1 gallon per minute, as Isoon discovered many of my neighbors were cursed with. Three gallonsper minute won't supply a fan nozzle or even a common impulsesprinkler, but I could still sustain my big raised-bed garden bywatering all night, five or six nights a week, with a single, 2-1/2gallon-per-minute sprinkler that I moved from place to place.I had repeatedly read that gardening in raised beds was the mostproductive vegetable growing method, required the least work, andwas the most water-efficient system ever known. So, without adequateirrigation, I would have concluded that food self-sufficiency on myhomestead was not possible. In late September of that first year, Icould still run that single sprinkler. What a relief not to haveinvested every last cent in land that couldn't feed us.For many succeeding years at Lorane, I raised lots of organicallygrown food on densely planted raised beds, but the realities ofbeing a country gardener continued to remind me of how tenuous myirrigation supply actually was. We country folks have to beself-reliant: I am my own sanitation department, I maintain my own800-foot-long driveway, the septic system puts me in the sewagebusiness. A long, long response time to my 911 call means I'm my ownself-defense force. And I'm my own water department.Without regular and heavy watering during high summer, dense standsof vegetables become stunted in a matter of days. Pump failure hasbrought my raised-bed garden close to that several times. Before myfrantic efforts got the water flowing again, I could feel thestressed-out garden screaming like a hungry baby.As I came to understand our climate, I began to wonder about'complete' food self-sufficiency. How did the early pioneersirrigate their vegetables? There probably aren't more than athousand homestead sites in the entire martitime Northwest withgravity water. Hand pumping into hand-carried buckets is impracticaland extremely tedious. Wind-powered pumps are expensive and havesevere limits.The combination of dependably rainless summers, the realities ofself-sufficient living, and my homestead's poor well turned out tobe an opportunity. For I continued wondering about gardens andwater, and discovered a method for growing a lush, productivevegetable garden on deep soil with little or no irrigation, in aclimate that reliably provides 8 to 12 virtually dry weeks everysummer.Gardening with Less IrrigationBeing a garden writer, I was on the receiving end of quite a bit oflocal lore. I had heard of someone growing unirrigated carrots onsandy soil in southern Oregon by sowing early and spacing the roots1 foot apart in rows 4 feet apart. The carrots were reputed to growto enormous sizes, and the overall yield in pounds per square footoccupied by the crop was not as low as one might think. I read thatNative Americans in the Southwest grew remarkable desert gardenswith little or no water. And that Native South Americans in thehighlands of Peru and Bolivia grow food crops in a land with 8 to 12inches of rainfall. So I had to wonder what our own pioneers did.In 1987, we moved 50 miles south, to a much better homestead withmore acreage and an abundant well. Ironically, only then did I growmy first summertime vegetable without irrigation. Being a low-keysurvivalist at heart, I was working at growing my own seeds. Themain danger to attaining good germination is in repeatedlymoistening developing seed. So, in early March 1988, I moved sixwinter-surviving savoy cabbage plants far beyond the irrigated soilof my raised-bed vegetable garden. I transplanted them 4 feet apartbecause blooming brassicas make huge sprays of flower stalks. I didnot plan to water these plants at all, since cabbage seed formsduring May and dries down during June as the soil naturally driesout.That is just what happened. Except that one plant did something alittle unusual, though not unheard of. Instead of completely goinginto bloom and then dying after setting a massive load of seed, thisplant also threw a vegetative bud that grew a whole new cabbageamong the seed stalks.With increasing excitement I watched this head grow steadily largerthrough the hottest and driest summer I had ever experienced.Realizing I was witnessing revelation, I gave the plant absolutelyno water, though I did hoe out the weeds around it after I cut theseed stalks. I harvested the unexpected lesson at the end ofSeptember. The cabbage weighed in at 6 or 7 pounds and was sweet andtender.Up to that time, all my gardening had been on thoroughly anduniformly watered raised beds. Now I saw that elbow room might bethe key to gardening with little or no irrigating, so I beganlooking for more information about dry gardening and soil/waterphysics. In spring 1989, I tilled four widely separated, unirrigatedexperimental rows in which I tested an assortment of vegetablespecies spaced far apart in the row. Out of curiosity I decided touse absolutely no water at all, not even to sprinkle the seeds toget them germinating.I sowed a bit of kale, savoy cabbage, Purple Sprouting broccoli,carrots, beets, parsnips, parsley, endive, dry beans, potatoes,French sorrel, and a couple of field cornstalks. I also tested onecompactbush (determinate) and one sprawling (indeterminate) tomatoplant. Many of these vegetables grew surprisingly well. I ateunwatered tomatoes July through September; kale, cabbages, parsley,and root crops fed us during the winter. The Purple Sproutingbroccoli bloomed abundantly the next March.In terms of quality, all the harvest was acceptable. The rootvegetables were far larger but only a little bit tougher and quite abit sweeter than usual. The potatoes yielded less than I'd been usedto and had thicker than usual skin, but also had a better flavor andkept well through the winter.The following year I grew two parallel gardens. One, my "insurancegarden," was thoroughly irrigated, guaranteeing we would have plentyto eat. Another experimental garden of equal size was entirelyunirrigated. There I tested larger plots of species that I hopedcould grow through a rainless summer.By July, growth on some species had slowed to a crawl and theylooked a little gnarly. Wondering if a hidden cause of what appearedto be moisture stress might actually be nutrient deficiencies, Itried spraying liquid fertilizer directly on these gnarly leaves, apractice called foliar feeding. It helped greatly because, Ireasoned, most fertility is located in the topsoil, and when it getsdry the plants draw on subsoil moisture, so surface nutrients,though still present in the dry soil, become unobtainable. Thatbeing so, I reasoned that some of these species might do even betterif they had just a little fertilized water. So I improvised a simpledrip system and metered out 4 or 5 gallons of liquid fertilizer tosome of the plants in late July and four gallons more in August. Tosome species, extra fertilized water (what I call "fertigation")hardly made any difference at all. But unirrigated winter squashvines, which were small and scraggly and yielded about 15 pounds offood, grew more lushly when given a few 5-gallon,fertilizer-fortified assists and yielded 50 pounds. Thirty-fivepounds of squash for 25 extra gallons of water and a bit of extranutrition is a pretty good exchange in my book.The next year I integrated all this new information into just onegarden. Water-loving species like lettuce and celery were grownthrough the summer on a large, thoroughly irrigated raised bed. Therest of the garden was given no irrigation at all or minimallymetered-out fertigations. Some unirrigated crops were foliar fedweekly.Everything worked in 1991! And I found still other species that Icould grow surprisingly well on surprisingly small amounts ofwater[--]or none at all. So, the next year, 1992, I set up asprinkler system to water the intensive raised bed and used theoverspray to support species that grew better with some moisturesupplementation; I continued using my improvised drip system to helpstill others, while keeping a large section of the garden entirelyunwatered. And at the end of that summer I wrote this book.What follows is not mere theory, not something I read about or sawothers do. These techniques are tested and workable. Thenext-to-last chapter of this book contains a complete plan of my1992 garden with explanations and discussion of the reasoning behindit.In 'Water-Wise Vegetables 'I assume that my readers already aregrowing food (probably on raised beds), already know how to adjusttheir gardening to this region's climate, and know how to gardenwith irrigation. If you don't have this background I suggest youread my other garden book, 'Growing Vegetables West of theCascades,' (Sasquatch Books, 1989).Steve SolomonChapter 1Predictably Rainless SummersIn the eastern United States, summertime rainfall can supportgardens without irrigation but is just irregular enough to beworrisome. West of the Cascades we go into the summer growing seasoncertain we must water regularly.My own many-times-revised book 'Growing Vegetables West of theCascades' correctly emphasized that moisture-stressed vegetablessuffer greatly. Because I had not yet noticed how plant spacingaffects soil moisture loss, in that book I stated a half-truth aslaw: Soil moisture loss averages 1-1/2 inches per week duringsummer.This figure is generally true for raised-bed gardens west of theCascades, so I recommended adding 1 1/2 inches of water each weekand even more during really hot weather.Summertime Rainfall West of the Cascades (in inches)*Location April May June July Aug. Sept. Oct.Eureka, CA 3.0 2.1 0.7 0.1 0.3 0.7 3.2Medford, OR 1.0 1.4 0.98 0.3 0.3 0.6 2.1Eugene, OR 2.3 2.1 1.3 0.3 0.6 1.3 4.0Portland, OR 2.2 2.1 1.6 0.5 0.8 1.6 3.6Astoria, OR 4.6 2.7 2.5 1.0 1.5 2.8 6.8Olympia, WA 3.1 1.9 1.6 0.7 1.2 2.1 5.3Seattle, WA 2.4 1.7 1.6 0.8 1.0 2.1 4.0Bellingham, WA 2.3 1.8 1.9 1.0 1.1 2.0 3.7Vancouver, BC 3.3 2.8 2.5 1.2 1.7 3.6 5.8Victoria, BC 1.2 1.0 0.9 0.4 0.6 1.5 2.8*Source: Van der Leeden et al., 'The Water Encyclopedia,' 2nded., (Chelsea, Mich.:Lewis Publishers, 1990).Defined scientifically, drought is not lack of rain. It is a drysoil condition in which plant growth slows or stops and plantsurvival may be threatened. The earth loses water when wind blows,when sun shines, when air temperature is high, and when humidity islow. Of all these factors, air temperature most affects soilmoisture loss.Daily Maximum Temperature (F)*July/August AverageEureka, CA 61Medford, OR 89Eugene, OR 82Astoria, OR 68Olympia, WA 78Seattle, WA 75Bellingham, WA 74Vancouver, BC 73Victoria, BC 68*Source: The Water Encyclopedia.The kind of vegetation growing on a particular plot and its densityhave even more to do with soil moisture loss than temperature orhumidity or wind speed. And, surprising as it might seem, bare soilmay not lose much moisture at all. I now know it is next toimpossible to anticipate moisture loss from soil without firstspecifying the vegetation there. Evaporation from a large body ofwater, however, is mainly determined by weather, so reservoirevaporation measurements serve as a rough gauge of anticipated soilmoisture loss.Evaporation from Reservoirs (inches per month)*Location April May June July Aug. Sept. OctSeattle, WA 2.1 2.7 3.4 3.9 3.4 2.6 1.6Baker, OR 2.5 3.4 4.4 6.9 7.3 4.9 2.9Sacramento, CA 3.6 5.0 7.1 8.9 8.6 7.1 4.8*Source: 'The Water Encyclopedia'From May through September during a normal year, a reservoir nearSeattle loses about 16 inches of water by evaporation. The nextchart shows how much water farmers expect to use to supportconventional agriculture in various parts of the West. Comparingthis data for Seattle with the estimates based on reservoirevaporation shows pretty good agreement. I include data for Umatillaand Yakima to show that much larger quantities of irrigation waterare needed in really hot, arid places like Baker or Sacramento.Estimated Irrigation Requirements: [ Pobierz całość w formacie PDF ]
zanotowane.pl doc.pisz.pl pdf.pisz.pl jajeczko.pev.pl
//-->Cascadia Gardening SeriesGardening Without Irrigation:or without much, anywaySteve SolomonIntroductionStarting a New Gardening EraFirst, you should know why a maritime Northwest raised-bed gardenernamed Steve Solomon became worried about his dependence onirrigation.I'm from Michigan. I moved to Lorane, Oregon, in April 1978 andhomesteaded on 5 acres in what I thought at the time was a cool,showery green valley of liquid sunshine and rainbows. I intended toput in a big garden and grow as much of my own food as possible.Two months later, in June, just as my garden began needing water, myso-called 15-gallon-per-minute well began to falter, yielding lessand less with each passing week. By August it delivered about 3gallons per minute. Fortunately, I wasn't faced with a completelydry well or one that had shrunk to below 1 gallon per minute, as Isoon discovered many of my neighbors were cursed with. Three gallonsper minute won't supply a fan nozzle or even a common impulsesprinkler, but I could still sustain my big raised-bed garden bywatering all night, five or six nights a week, with a single, 2-1/2gallon-per-minute sprinkler that I moved from place to place.I had repeatedly read that gardening in raised beds was the mostproductive vegetable growing method, required the least work, andwas the most water-efficient system ever known. So, without adequateirrigation, I would have concluded that food self-sufficiency on myhomestead was not possible. In late September of that first year, Icould still run that single sprinkler. What a relief not to haveinvested every last cent in land that couldn't feed us.For many succeeding years at Lorane, I raised lots of organicallygrown food on densely planted raised beds, but the realities ofbeing a country gardener continued to remind me of how tenuous myirrigation supply actually was. We country folks have to beself-reliant: I am my own sanitation department, I maintain my own800-foot-long driveway, the septic system puts me in the sewagebusiness. A long, long response time to my 911 call means I'm my ownself-defense force. And I'm my own water department.Without regular and heavy watering during high summer, dense standsof vegetables become stunted in a matter of days. Pump failure hasbrought my raised-bed garden close to that several times. Before myfrantic efforts got the water flowing again, I could feel thestressed-out garden screaming like a hungry baby.As I came to understand our climate, I began to wonder about'complete' food self-sufficiency. How did the early pioneersirrigate their vegetables? There probably aren't more than athousand homestead sites in the entire martitime Northwest withgravity water. Hand pumping into hand-carried buckets is impracticaland extremely tedious. Wind-powered pumps are expensive and havesevere limits.The combination of dependably rainless summers, the realities ofself-sufficient living, and my homestead's poor well turned out tobe an opportunity. For I continued wondering about gardens andwater, and discovered a method for growing a lush, productivevegetable garden on deep soil with little or no irrigation, in aclimate that reliably provides 8 to 12 virtually dry weeks everysummer.Gardening with Less IrrigationBeing a garden writer, I was on the receiving end of quite a bit oflocal lore. I had heard of someone growing unirrigated carrots onsandy soil in southern Oregon by sowing early and spacing the roots1 foot apart in rows 4 feet apart. The carrots were reputed to growto enormous sizes, and the overall yield in pounds per square footoccupied by the crop was not as low as one might think. I read thatNative Americans in the Southwest grew remarkable desert gardenswith little or no water. And that Native South Americans in thehighlands of Peru and Bolivia grow food crops in a land with 8 to 12inches of rainfall. So I had to wonder what our own pioneers did.In 1987, we moved 50 miles south, to a much better homestead withmore acreage and an abundant well. Ironically, only then did I growmy first summertime vegetable without irrigation. Being a low-keysurvivalist at heart, I was working at growing my own seeds. Themain danger to attaining good germination is in repeatedlymoistening developing seed. So, in early March 1988, I moved sixwinter-surviving savoy cabbage plants far beyond the irrigated soilof my raised-bed vegetable garden. I transplanted them 4 feet apartbecause blooming brassicas make huge sprays of flower stalks. I didnot plan to water these plants at all, since cabbage seed formsduring May and dries down during June as the soil naturally driesout.That is just what happened. Except that one plant did something alittle unusual, though not unheard of. Instead of completely goinginto bloom and then dying after setting a massive load of seed, thisplant also threw a vegetative bud that grew a whole new cabbageamong the seed stalks.With increasing excitement I watched this head grow steadily largerthrough the hottest and driest summer I had ever experienced.Realizing I was witnessing revelation, I gave the plant absolutelyno water, though I did hoe out the weeds around it after I cut theseed stalks. I harvested the unexpected lesson at the end ofSeptember. The cabbage weighed in at 6 or 7 pounds and was sweet andtender.Up to that time, all my gardening had been on thoroughly anduniformly watered raised beds. Now I saw that elbow room might bethe key to gardening with little or no irrigating, so I beganlooking for more information about dry gardening and soil/waterphysics. In spring 1989, I tilled four widely separated, unirrigatedexperimental rows in which I tested an assortment of vegetablespecies spaced far apart in the row. Out of curiosity I decided touse absolutely no water at all, not even to sprinkle the seeds toget them germinating.I sowed a bit of kale, savoy cabbage, Purple Sprouting broccoli,carrots, beets, parsnips, parsley, endive, dry beans, potatoes,French sorrel, and a couple of field cornstalks. I also tested onecompactbush (determinate) and one sprawling (indeterminate) tomatoplant. Many of these vegetables grew surprisingly well. I ateunwatered tomatoes July through September; kale, cabbages, parsley,and root crops fed us during the winter. The Purple Sproutingbroccoli bloomed abundantly the next March.In terms of quality, all the harvest was acceptable. The rootvegetables were far larger but only a little bit tougher and quite abit sweeter than usual. The potatoes yielded less than I'd been usedto and had thicker than usual skin, but also had a better flavor andkept well through the winter.The following year I grew two parallel gardens. One, my "insurancegarden," was thoroughly irrigated, guaranteeing we would have plentyto eat. Another experimental garden of equal size was entirelyunirrigated. There I tested larger plots of species that I hopedcould grow through a rainless summer.By July, growth on some species had slowed to a crawl and theylooked a little gnarly. Wondering if a hidden cause of what appearedto be moisture stress might actually be nutrient deficiencies, Itried spraying liquid fertilizer directly on these gnarly leaves, apractice called foliar feeding. It helped greatly because, Ireasoned, most fertility is located in the topsoil, and when it getsdry the plants draw on subsoil moisture, so surface nutrients,though still present in the dry soil, become unobtainable. Thatbeing so, I reasoned that some of these species might do even betterif they had just a little fertilized water. So I improvised a simpledrip system and metered out 4 or 5 gallons of liquid fertilizer tosome of the plants in late July and four gallons more in August. Tosome species, extra fertilized water (what I call "fertigation")hardly made any difference at all. But unirrigated winter squashvines, which were small and scraggly and yielded about 15 pounds offood, grew more lushly when given a few 5-gallon,fertilizer-fortified assists and yielded 50 pounds. Thirty-fivepounds of squash for 25 extra gallons of water and a bit of extranutrition is a pretty good exchange in my book.The next year I integrated all this new information into just onegarden. Water-loving species like lettuce and celery were grownthrough the summer on a large, thoroughly irrigated raised bed. Therest of the garden was given no irrigation at all or minimallymetered-out fertigations. Some unirrigated crops were foliar fedweekly.Everything worked in 1991! And I found still other species that Icould grow surprisingly well on surprisingly small amounts ofwater[--]or none at all. So, the next year, 1992, I set up asprinkler system to water the intensive raised bed and used theoverspray to support species that grew better with some moisturesupplementation; I continued using my improvised drip system to helpstill others, while keeping a large section of the garden entirelyunwatered. And at the end of that summer I wrote this book.What follows is not mere theory, not something I read about or sawothers do. These techniques are tested and workable. Thenext-to-last chapter of this book contains a complete plan of my1992 garden with explanations and discussion of the reasoning behindit.In 'Water-Wise Vegetables 'I assume that my readers already aregrowing food (probably on raised beds), already know how to adjusttheir gardening to this region's climate, and know how to gardenwith irrigation. If you don't have this background I suggest youread my other garden book, 'Growing Vegetables West of theCascades,' (Sasquatch Books, 1989).Steve SolomonChapter 1Predictably Rainless SummersIn the eastern United States, summertime rainfall can supportgardens without irrigation but is just irregular enough to beworrisome. West of the Cascades we go into the summer growing seasoncertain we must water regularly.My own many-times-revised book 'Growing Vegetables West of theCascades' correctly emphasized that moisture-stressed vegetablessuffer greatly. Because I had not yet noticed how plant spacingaffects soil moisture loss, in that book I stated a half-truth aslaw: Soil moisture loss averages 1-1/2 inches per week duringsummer.This figure is generally true for raised-bed gardens west of theCascades, so I recommended adding 1 1/2 inches of water each weekand even more during really hot weather.Summertime Rainfall West of the Cascades (in inches)*Location April May June July Aug. Sept. Oct.Eureka, CA 3.0 2.1 0.7 0.1 0.3 0.7 3.2Medford, OR 1.0 1.4 0.98 0.3 0.3 0.6 2.1Eugene, OR 2.3 2.1 1.3 0.3 0.6 1.3 4.0Portland, OR 2.2 2.1 1.6 0.5 0.8 1.6 3.6Astoria, OR 4.6 2.7 2.5 1.0 1.5 2.8 6.8Olympia, WA 3.1 1.9 1.6 0.7 1.2 2.1 5.3Seattle, WA 2.4 1.7 1.6 0.8 1.0 2.1 4.0Bellingham, WA 2.3 1.8 1.9 1.0 1.1 2.0 3.7Vancouver, BC 3.3 2.8 2.5 1.2 1.7 3.6 5.8Victoria, BC 1.2 1.0 0.9 0.4 0.6 1.5 2.8*Source: Van der Leeden et al., 'The Water Encyclopedia,' 2nded., (Chelsea, Mich.:Lewis Publishers, 1990).Defined scientifically, drought is not lack of rain. It is a drysoil condition in which plant growth slows or stops and plantsurvival may be threatened. The earth loses water when wind blows,when sun shines, when air temperature is high, and when humidity islow. Of all these factors, air temperature most affects soilmoisture loss.Daily Maximum Temperature (F)*July/August AverageEureka, CA 61Medford, OR 89Eugene, OR 82Astoria, OR 68Olympia, WA 78Seattle, WA 75Bellingham, WA 74Vancouver, BC 73Victoria, BC 68*Source: The Water Encyclopedia.The kind of vegetation growing on a particular plot and its densityhave even more to do with soil moisture loss than temperature orhumidity or wind speed. And, surprising as it might seem, bare soilmay not lose much moisture at all. I now know it is next toimpossible to anticipate moisture loss from soil without firstspecifying the vegetation there. Evaporation from a large body ofwater, however, is mainly determined by weather, so reservoirevaporation measurements serve as a rough gauge of anticipated soilmoisture loss.Evaporation from Reservoirs (inches per month)*Location April May June July Aug. Sept. OctSeattle, WA 2.1 2.7 3.4 3.9 3.4 2.6 1.6Baker, OR 2.5 3.4 4.4 6.9 7.3 4.9 2.9Sacramento, CA 3.6 5.0 7.1 8.9 8.6 7.1 4.8*Source: 'The Water Encyclopedia'From May through September during a normal year, a reservoir nearSeattle loses about 16 inches of water by evaporation. The nextchart shows how much water farmers expect to use to supportconventional agriculture in various parts of the West. Comparingthis data for Seattle with the estimates based on reservoirevaporation shows pretty good agreement. I include data for Umatillaand Yakima to show that much larger quantities of irrigation waterare needed in really hot, arid places like Baker or Sacramento.Estimated Irrigation Requirements: [ Pobierz całość w formacie PDF ]