Dryland farming - Revision history

Kevin Smith: /* www.greatgreenwallinitiative.orgFurther reading */

2014-11-17T16:58:30Z

‎www.greatgreenwallinitiative.orgFurther reading

Kevin Smith: /* Further reading */

2014-11-17T16:57:59Z

‎Further reading

Irena Irmler at 10:31, 20 February 2014

2014-02-20T10:31:19Z

Show changes

Irena Irmler at 10:22, 20 February 2014

2014-02-20T10:22:08Z

Irena Irmler at 11:59, 13 January 2014

2014-01-13T11:59:01Z

Show changes

Brian Chatterton: /* Alternative sources of nitrogen */

2013-12-31T17:05:36Z

‎Alternative sources of nitrogen

Brian Chatterton: /* What is dryland farming? */

2013-12-31T17:04:29Z

‎What is dryland farming?

Brian Chatterton: /* References: */

2013-12-31T16:56:56Z

‎References:

Brian Chatterton: /* Introduction */

2013-12-31T16:56:41Z

‎Introduction

Brian Chatterton: /* Introduction */

2013-12-31T16:56:26Z

‎Introduction

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-= [http://www.greatgreenwallinitiative.org www.greatgreenwallinitiative.orgFurther] reading =
 Dryland Farming Organisation. [http://www.drylandfarming.org/ www.drylandfarming.org]<br/>
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 Great Green Wall for the Sahara and the Sahel Initiative [http://www.greatgreenwallinitiative.org www.greatgreenwallinitiative.org]
 [[Category:Good_Practices]]

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 Squires, V. and Tow, P., Dryland Farming: A Systems Approach - An Analysis of Dryland Agriculture in Australia (Sydney: Sydney University Press, 1991)
-= Further reading =
 Dryland Farming Organisation. [http://www.drylandfarming.org/ www.drylandfarming.org]<br/>
-[[Category:Good_Practices]]
+Great Green Wall for the Sahara and the Sahel Initiative [http://www.greatgreenwallinitiative.org www.greatgreenwallinitiative.org]
-[[Category:Excellent]]
 [[Category:Technologies]]

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-Dryland farming is a type of farming practiced in arid areas without irrigation by planting drought-resistant crops and maintaining a fine surface tilth or mulch that protects the natural moisture of the soil from evaporation. At a time of increased water stress in semi-arid regions, dryland farming will play a pivotal role for food security in the coming decades (Chatteron 1996; Squires and Tow 1991; Malcolm, Sale & Egan 1996; Drylandfarming.org 2013).
+Dryland farming is a type of farming practiced in arid areas without [[Deficit_irrigation|irrigation]] by planting [[Proactive_management_of_flooding_and_drought|drought]]-resistant [[Crop_water_requirements|crops]] and maintaining a fine surface tilth or mulch that protects the natural moisture of the [[Relevance_of_soil|soil]] from evaporation. At a time of increased [[Water_scarcity|water stress]] in semi-arid regions, dryland farming will play a pivotal role for [[Definition_and_Dimensions_of_Food_Security|food security]] in the coming decades (Chatteron 1996; Squires and Tow 1991; Malcolm, Sale & Egan 1996; Drylandfarming.org 2013).<br/>
 = What is dryland farming? =
-Farming systems need to be compatible with both climate and environment if they are to be sustainable. They also need to be profitable for farmers.
+Farming systems need to be compatible with both [[Climate_Change_and_Agriculture|climate]] and environment if they are to be [[Sustainable_intensification|sustainable]]. They also need to be [[Incomes_and_livelihoods_related_to_agricultural_water_management|profitable]] for farmers.
-London, Tunis and Adelaide all have about the same annual rainfall of 500 mm. Tunis and Adelaide are in the centre of dryland farming zones while London is typical of a humid temperate climate. The growing season in the temperate regions is limited by low temperatures and short days in winter. The summer moisture deficit in London rarely reaches 50 mm. In dryland farming zones such as Tunis and Adelaide the winters are mild and humid but the summers are hot and dry. The moisture deficit in summer is perhaps 1000 mm. Crop and pasture growth stops completely. Summer droughts occur in temperate farming regions from time to time but within dryland farming zones they are permanent feature of the farming year. A winter rainfall pattern is typical of Mediterranean dryland farming zones. These zones are found on the southern shore of the Mediterranean, West Asia, Southern Australia, Chile and California (Chatterton 1996; Drylandfarming.org 2013).
+London, Tunis and Adelaide all have about the same annual rainfall of 500 mm. Tunis and Adelaide are in the centre of dryland farming zones while London is typical of a humid temperate climate. The growing season in the temperate regions is limited by low temperatures and short days in winter. The summer moisture deficit in London rarely reaches 50 mm. In dryland farming zones such as Tunis and Adelaide the winters are mild and humid but the summers are hot and dry. The moisture deficit in summer is perhaps 1000 mm. Crop and pasture growth stops completely. Summer droughts occur in temperate farming regions from time to time but within dryland farming zones they are permanent feature of the farming year. A winter [[Precipitation|rainfall]] pattern is typical of Mediterranean dryland farming zones. These zones are found on the southern shore of the Mediterranean, West Asia, Southern Australia, Chile and California (Chatterton 1996; Drylandfarming.org 2013).
 [[File:Drylandfarming.png|481px|RTENOTITLE]]<br/>
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 <br/>
-<br/>
+The map illustrates the difficulty of translating simple climatic parameters into farming zones. The pale green and orange coloured areas are clearly dryland farming zones. The Dark brown is clearly humid temperate but the dark green area classed as “high rainfall” Mediterranean which is an intermediate dryland farming zone. The summer droughts are shorter. Winter and spring rains are heavier and more reliable. A sustainable and profitable dryland farming system for these Mediterranean dryland regions was evolved in the 19<sup>th</sup> and 20<sup>th</sup> centuries by farmers in South Australia. It is based on self regenerating annual medicago (medic) and clovers and enables farmers to [[Small-scale_Agriculture_on_Acid_Soils#Crop_Rotation|rotate]] crops of grain with pasture for sheep in a productive and low cost rotation. In its traditional Australian form the pasture is established and the seed reserves in the soil are safeguarded by ensuring that during seed bed preparation for the subsequent grain crop, deep ploughing is abandoned in favour of shallow [[Contour_furrows,_ridges,_strip_cultivation|cultivation]]. Shallow cultivation is energy and fuel [[Better_Water_Use_Efficiency_for_Increasing_Yields_and_Food_Security_-_from_Watersheds_to_Field|efficient]] and saves time and labour. Shallow cultivation is essential as it protects the pasture seed and enables it to regenerate each spring without further seeding. Variations of this traditional rotation have been developed in North Africa that combine the medic with conventional fallowing. Nitrogen fertiliser is not used as the pasture produces sufficient [[Relevance_of_soil|soil]] nitrogen for grain crops. An application of superphosphate will ensure that the pasture remains abundant. Grazing is managed to ensure high levels of seed production. A rotation of grain and pasture becomes the basis of the farming system with a portion of the farmland in pasture and a portion in grain each year and variations depending on the climate and market signals. Dryland farming also refers to zones in the tropics where the growing season is limited by a seasonal drought. The rainfall in the tropics is during the summer while the winter is the dry season. Because temperatures and evapo-transpiration rates are much higher in summer tropical dryland farming requires about double the amount of annual rainfall for similar levels of production. Annual, self-regenerating, legume pastures are available for the dry tropics but they have not yet been developed into a practical farming system (Chatterton 1996).
-−
 The map illustrates the difficulty of translating simple climatic parameters into farming zones. The pale green and orange coloured areas are clearly dryland farming zones. The Dark brown is clearly humid temperate but the dark green area classed as “high rainfall” Mediterranean which is an intermediate dryland farming zone. The summer droughts are shorter. Winter and spring rains are heavier and more reliable. A sustainable and profitable dryland farming system for these Mediterranean dryland regions was evolved in the 19<sup>th</sup> and 20<sup>th</sup> centuries by farmers in South Australia. It is based on self regenerating annual medicago (medic) and clovers and enables farmers to rotate crops of grain with pasture for sheep in a productive and low cost rotation. In its traditional Australian form the pasture is established and the seed reserves in the soil are safeguarded by ensuring that during seed bed preparation for the subsequent grain crop, deep ploughing is abandoned in favour of shallow cultivation. Shallow cultivation is energy and fuel efficient and saves time and labour. Shallow cultivation is essential as it protects the pasture seed and enables it to regenerate each spring without further seeding. Variations of this traditional rotation have been developed in North Africa that combine the medic with conventional fallowing. Nitrogen fertiliser is not used as the pasture produces sufficient soil nitrogen for grain crops. An application of superphosphate will ensure that the pasture remains abundant. Grazing is managed to ensure high levels of seed production. A rotation of grain and pasture becomes the basis of the farming system with a portion of the farmland in pasture and a portion in grain each year and variations depending on the climate and market signals. Dryland farming also refers to zones in the tropics where the growing season is limited by a seasonal drought. The rainfall in the tropics is during the summer while the winter is the dry season. Because temperatures and evapo-transpiration rates are much higher in summer tropical dryland farming requires about double the amount of annual rainfall for similar levels of production. Annual, self-regenerating, legume pastures are available for the dry tropics but they have not yet been developed into a practical farming system (Chatterton 1996).
 = The Green Revolution =
-Over the last half century the green revolution has transformed cereal production in the temperate rain fed regions and areas with irrigation. The Green Revolution is not “green” in the modern sense as it is a high input farming system that exploits some non-renewable resources. The three major inputs are water from ample rainfall or irrigation, large quantities of nitrogen fertiliser produced from petroleum and cereal cultivars that can convert the water and nitrogen into high grain yields. In dryland farming areas the water supply is unreliable. In the Mediterranean dryland farming zones the spring rainfall is critical for the development of good grain yields. The use of nitrogen fertiliser produces erratic results. The application of nitrogen encourages the cereal plant to tiller - that is to produce more side shoots. These shoots produce seed heads and then grain. If spring rains are poor the grain does not mature and because of the increased competition between tillers the yield may be lower than that from a crop that does not receive nitrogen fertiliser.
+Over the last half century the green revolution has transformed cereal production in the temperate rain fed regions and areas with [[Drainage_and_irrigation|irrigation]]. The Green Revolution is not “green” in the modern sense as it is a high input farming system that exploits some non-renewable resources. The three major inputs are water from ample rainfall or irrigation, large quantities of nitrogen fertiliser produced from petroleum and cereal cultivars that can convert the water and nitrogen into high grain [[Better_Water_Use_Efficiency_for_Increasing_Yields_and_Food_Security_-_from_Watersheds_to_Field|yields]]. In dryland farming areas the water supply is unreliable. In the Mediterranean dryland farming zones the spring rainfall is critical for the development of good grain yields. The use of nitrogen fertiliser produces erratic results. The application of nitrogen encourages the cereal plant to tiller - that is to produce more side shoots. These shoots produce seed heads and then grain. If spring rains are poor the grain does not mature and because of the increased competition between tillers the yield may be lower than that from a crop that does not receive nitrogen fertiliser.
-This is not a startling new discovery. Experiments conducted at the Roseworthy Agricultural College in the South Australian dryland farming zone in the 1880's showed that the application of nitrogen fertiliser produced such variable results that farmers were not advised to use it. The effectiveness of nitrogen depends on the spring rainfall. Where the annual rainfall is above 500 mm in the Mediterranean dryland farming zone the response to nitrogen fertiliser is more reliable while below 500 mm the risks are much greater. In some years there will be no yield response or even a reduction in yield. The application of nitrogen is not only a technical question. The response curve is the core of the decision making process but the farmer also needs to calculate the cost and benefit from the price of the fertiliser and the return from the cereal crop. Nitrogen fertilisers have generally been cheap over the last hundred years but have increased dramatically in price with increases in energy prices. Grain prices have generally fallen in real terms. Over the last decade or so both grain prices and fertiliser prices have increased. The true price of the nitrogen fertiliser is not reflected in the price paid by farmers and entered into their profit and loss accounts. Nitrogen fertiliser is solid or liquid energy from fossil carbon sources. When it is applied to the soil it is converted by soil bacteria into various compounds of nitrogen that can be absorbed by the plants. During the conversion process oxides of nitrogen are released into the atmosphere. These are about 300 times more polluting than carbon dioxide in terms of the green house effect. Instead of taxing nitrogen fertiliser to reflect these environmental costs governments are more likely to subsidise it. The amount of nitrogen lost to the atmosphere varies according to climatic conditions but inadequate rainfall and rising temperatures as found in dryland farming zones during the spring are conducive to higher levels of loss. The third factor in the decision making process is risk. Risks are greater for small farmers with few resources of capital or credit compared to the larger farmers. The risk of zero or negative returns from nitrogen fertiliser are greater in low rainfall areas compared to higher rainfall zones. In Australia farms are larger in lower rainfall zones but that is not the case in many other dryland farming regions of the world. For example in North Africa due to the colonial legacy farms are often smaller in the more marginal zones. These farmers are unlikely to take on the additional risks associated with nitrogen fertilizer (Chatterton 1996)..
+This is not a startling new discovery. Experiments conducted at the Roseworthy Agricultural College in the South Australian dryland farming zone in the 1880's showed that the application of nitrogen fertiliser produced such variable results that farmers were not advised to use it. The effectiveness of nitrogen depends on the spring rainfall. Where the annual rainfall is above 500 mm in the Mediterranean dryland farming zone the response to nitrogen fertiliser is more reliable while below 500 mm the risks are much greater. In some years there will be no yield response or even a reduction in yield. The application of nitrogen is not only a technical question. The response curve is the core of the decision making process but the farmer also needs to[[Applying_cost-benefit-analysis_to_irrigation_projects_and_programs|calculate the cost and benefit]] from the price of the fertiliser and the return from the cereal crop. Nitrogen fertilisers have generally been cheap over the last hundred years but have increased dramatically in price with increases in [[Water,_energy_and_food_nexus|energy]] prices. Grain prices have generally fallen in real terms. Over the last decade or so both grain prices and fertiliser prices have increased. The true price of the nitrogen fertiliser is not reflected in the price paid by farmers and entered into their profit and loss accounts. Nitrogen fertiliser is solid or liquid energy from fossil carbon sources. When it is applied to the soil it is converted by soil bacteria into various compounds of nitrogen that can be absorbed by the plants. During the conversion process oxides of nitrogen are released into the atmosphere. These are about 300 times more polluting than carbon dioxide in terms of the [[Climate_Change_and_Agriculture|green house effect]]. Instead of taxing nitrogen fertiliser to reflect these environmental costs governments are more likely to subsidise it. The amount of nitrogen lost to the atmosphere varies according to climatic conditions but inadequate rainfall and rising temperatures as found in dryland farming zones during the spring are conducive to higher levels of loss. The third factor in the decision making process is risk. [[Corporate_water_risks|Risks]] are greater for [[Small-scale_Agriculture_on_Acid_Soils|small farmers]] with few resources of capital or credit compared to the larger farmers. The risk of zero or negative returns from nitrogen fertiliser are greater in low rainfall areas compared to higher rainfall zones. In Australia farms are larger in lower rainfall zones but that is not the case in many other dryland farming regions of the world. For example in North Africa due to the colonial legacy farms are often smaller in the more marginal zones. These farmers are unlikely to take on the additional risks associated with nitrogen fertilizer (Chatterton 1996)..
 = Alternative sources of nitrogen =
-For more than one hundred years the scientific community has been searching for alternative sources of soil fertility. One of the first options, promoted in the first half of the 20<sup>th</sup> century, was the the long cultivated fallow. The land was cultivated in the spring and left bare during the summer. In the autumn the cereal crop was sown. At first this was advocated as a means of carrying soil moisture over from one season to the next but this theory has been comprehensively discredited. However the cultivated fallow did work. It increased yields through better weed control and the mobilisation of organic nitrogen.
+For more than one hundred years the scientific community has been searching for alternative sources of soil [[File:Resilience_changing_practices_Soil_fertility_2009.pdf|fertility]]. One of the first options, promoted in the first half of the 20<sup>th</sup> century, was the the long cultivated fallow. The land was cultivated in the spring and left bare during the summer. In the autumn the cereal crop was sown. At first this was advocated as a means of carrying soil moisture over from one season to the next but this theory has been comprehensively discredited. However the cultivated fallow did work. It increased yields through better weed control and the mobilisation of organic nitrogen.
 <br/>
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 {| cellspacing="0" cellpadding="0" border="0"
 |-
-| style="width:442px" rowspan="2" |
+| rowspan="2" style="width:442px" |
 <br/>Dryland farming rotations
-| style="width:203px" colspan="2" |
+| colspan="2" style="width:203px" |
 Means yield of wheat Kg/ha
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 {| cellspacing="0" cellpadding="0" border="0"
 |-
-| style="width:177px" rowspan="2" |
+| rowspan="2" style="width:177px" |
 <br/>
-| style="width:324px" colspan="2" |
+| colspan="2" style="width:324px" |
 South Australia
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 = Further reading =
-Dryland Farming Organisation. [http://www.drylandfarming.org/ www.drylandfarming.org]
+Dryland Farming Organisation. [http://www.drylandfarming.org/ www.drylandfarming.org]<br/>
 [[Category:Technologies]]

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 <br/>
 = '''Alternative sources of nitrogen''' =
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 <br/>
 = '''The legume pastures come to North Africa and West Asia''' =

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 Dryland farming is <span style="line-height: 1.5em; font-size: 0.85em;">a type of farming practiced in arid areas without irrigation by planting drought-resistant crops and maintaining a fine surface tilth or mulch that protects the natural moisture of the soil from evaporation. At a time of increased water stress in semi-arid regions, dryland farming will play a pivotal role for food security in the coming decades (Chatteron 1996; Squires and Tow 1991; Malcolm, Sale & Egan 1996; Drylandfarming.org 2013).</span>
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 London, Tunis and Adelaide all have about the same annual rainfall of 500 mm. Tunis and Adelaide are in the centre of dryland farming zones while London is typical of a humid temperate climate. The growing season in the temperate regions is limited by low temperatures and short days in winter. The summer moisture deficit in London rarely reaches 50 mm. In dryland farming zones such as Tunis and Adelaide the winters are mild and humid but the summers are hot and dry. The moisture deficit in summer is perhaps 1000 mm. Crop and pasture growth stops completely. Summer droughts occur in temperate farming regions from time to time but within dryland farming zones they are permanent feature of the farming year. A winter rainfall pattern is typical of Mediterranean dryland farming zones. These zones are found on the southern shore of the Mediterranean, West Asia, Southern Australia, Chile and California (Chatterton 1996; Drylandfarming.org 2013).
-<br/>
+[[File:Drylandfarming.png]]<br/>
 <br/>
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 <br/>
-The above map illustrates that difficulty of translating simple climatic parameters into farming zones. The pale green and orange coloured areas are clearly dryland farming zones. The Dark brown is clearly humid temperate but the dark green area classed as “high rainfall” Mediterranean which is an intermediate dryland farming zone. The summer droughts are shorter. Winter and spring rains are heavier and more reliable. A sustainable and profitable dryland farming system for these Mediterranean dryland regions was evolved in the 19<sup>th</sup> and 20<sup>th</sup> centuries by farmers in South Australia. It is based on self regenerating annual medicago (medic) and clovers and enables farmers to rotate crops of grain with pasture for sheep in a productive and low cost rotation. In its traditional Australian form the pasture is established and the seed reserves in the soil are safeguarded by ensuring that during seed bed preparation for the subsequent grain crop, deep ploughing is abandoned in favour of shallow cultivation. Shallow cultivation is energy and fuel efficient and saves time and labour. Shallow cultivation is essential as it protects the pasture seed and enables it to regenerate each spring without further seeding. Variations of this traditional rotation have been developed in North Africa that combine the medic with conventional fallowing. Nitrogen fertiliser is not used as the pasture produces sufficient soil nitrogen for grain crops. An application of superphosphate will ensure that the pasture remains abundant. Grazing is managed to ensure high levels of seed production. A rotation of grain and pasture becomes the basis of the farming system with a portion of the farmland in pasture and a portion in grain each year and variations depending on the climate and market signals. Dryland farming also refers to zones in the tropics where the growing season is limited by a seasonal drought. The rainfall in the tropics is during the summer while the winter is the dry season. Because temperatures and evapo-transpiration rates are much higher in summer tropical dryland farming requires about double the amount of annual rainfall for similar levels of production. Annual, self-regenerating, legume pastures are available for the dry tropics but they have not yet been developed into a practical farming system (Chatterton 1996).
+The map illustrates the difficulty of translating simple climatic parameters into farming zones. The pale green and orange coloured areas are clearly dryland farming zones. The Dark brown is clearly humid temperate but the dark green area classed as “high rainfall” Mediterranean which is an intermediate dryland farming zone. The summer droughts are shorter. Winter and spring rains are heavier and more reliable. A sustainable and profitable dryland farming system for these Mediterranean dryland regions was evolved in the 19<sup>th</sup> and 20<sup>th</sup> centuries by farmers in South Australia. It is based on self regenerating annual medicago (medic) and clovers and enables farmers to rotate crops of grain with pasture for sheep in a productive and low cost rotation. In its traditional Australian form the pasture is established and the seed reserves in the soil are safeguarded by ensuring that during seed bed preparation for the subsequent grain crop, deep ploughing is abandoned in favour of shallow cultivation. Shallow cultivation is energy and fuel efficient and saves time and labour. Shallow cultivation is essential as it protects the pasture seed and enables it to regenerate each spring without further seeding. Variations of this traditional rotation have been developed in North Africa that combine the medic with conventional fallowing. Nitrogen fertiliser is not used as the pasture produces sufficient soil nitrogen for grain crops. An application of superphosphate will ensure that the pasture remains abundant. Grazing is managed to ensure high levels of seed production. A rotation of grain and pasture becomes the basis of the farming system with a portion of the farmland in pasture and a portion in grain each year and variations depending on the climate and market signals. Dryland farming also refers to zones in the tropics where the growing season is limited by a seasonal drought. The rainfall in the tropics is during the summer while the winter is the dry season. Because temperatures and evapo-transpiration rates are much higher in summer tropical dryland farming requires about double the amount of annual rainfall for similar levels of production. Annual, self-regenerating, legume pastures are available for the dry tropics but they have not yet been developed into a practical farming system (Chatterton 1996).
 <br/>
 = '''The green revolution''' =

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 <br/>
-= References: =
 <br/>

← Older revision		Revision as of 16:56, 31 December 2013
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	= '''Introduction''' =		= '''Introduction''' =

−	~~'''~~Dryland farming is ~~'''~~<span style="line-height: 1.5em; font-size: 0.85em;">a type of farming practiced in arid areas without irrigation by planting drought-resistant crops and maintaining a fine surface tilth or mulch that protects the natural moisture of the soil from evaporation. At a time of increased water stress in semi-arid regions, dryland farming will play a pivotal role for food security in the coming decades (Chatteron 1996; Squires and Tow 1991; Malcolm, Sale & Egan 1996; Drylandfarming.org 2013).</span>	+	Dryland farming is <span style="line-height: 1.5em; font-size: 0.85em;">a type of farming practiced in arid areas without irrigation by planting drought-resistant crops and maintaining a fine surface tilth or mulch that protects the natural moisture of the soil from evaporation. At a time of increased water stress in semi-arid regions, dryland farming will play a pivotal role for food security in the coming decades (Chatteron 1996; Squires and Tow 1991; Malcolm, Sale & Egan 1996; Drylandfarming.org 2013).</span>