North America

Conservation tillage techniques have rapidly become popular ways of preparing fields for cropping because of their many environmental and economic benefits. Non-selective herbicides like paraquat are essential components of conservation tillage because fields are not plowed to bury weeds, and desiccated vegetation, stover and stubble provide a protective cover to the soil. This helps to minimise erosion, provides habitats for beneficial insects and other wildlife, and undisturbed soil builds higher levels of organic matter, key to good soil structure and fertility.
Why do farmers adopt conservation tillage?
Benefits of conservation tillage Less soil erosion
Better soil structure & fertility
More biodiversity
Quick crop establishment
Less labor
Less machinery required
Less fuel used
Reduced greenhouse gas emissions
Lower costs
Cheaper food
 In the US, cropland under conservation tillage has continued to increase year on year as farmers see the value in putting away their plows. The Conservation Technology Information Center (CITC) estimates that over 40% of all crops in the US are now under conservation tillage practices. 
The gold standard is no-till in which there are no soil cultivations at all. Other forms of conservation tillage are shown in the box below.
This season has seen a redoubling of efforts to fight the spread of glyphosate resistant Palmer amaranth (Amaranthus palmeri) in US crops. The key to resistance management is to use herbicides which have different modes of action. When it comes to achieving a broad-spectrum effect like glyphosate, the choice of alternatives is extremely limited. Paraquat’s unique mode of action1 together with its broad-spectrum weed control and fast action, make it an invaluable tool in the fight against weed resistance to glyphosate.
Palmer amaranth is one of several important weed species in the same genus (Amaranthus) commonly known as pigweeds or waterhemps. It is a major problem in many southern states, particularly in Georgia, where it is considered to be the number one weed problem in cotton.
Weed scientists at the University of Georgia estimate that an average of just two Palmer amaranth plants in every 6 m (about 20 feet) length of cotton row can reduce yield by at least 23%. Furthermore, when a single plant can produce an alarming 450,000 seeds, you can bet the problem will be worse the next season.
Paraquat, used in a conservation tillage system, has reaped rewards for two Virginia cotton growers. Brothers Cliff and Clarke Fox of Foxhill Farms have been named Farm Press High Cotton Award winners for the Southeast region.
The Fox brothers planted their first crop of cotton in 1994, using traditional tilling methods. They began the switch to conservation tillage with their second crop. Today, their conservation tillage approach is firmly established.
As reported in a January 5, 2006 article in the SouthEast Farms Press, for their award-winning crop, the brothers “use a burn down herbicide, either glyphosate or paraquat, depending on the weed history of the field and time of application.”
Low- or no-till farming benefits land by helping to reduce soil erosion and conserving soil moisture. Paraquat contributes significantly to conservation tillage systems - such as those used by Foxhill Farms - by controlling weeds with its fast, contact-only action, which kills weeds while leaving root structures intact.
Congratulations to Cliff and Clarke Fox of Foxhill Farms. View the complete story on the SouthEast Farms Press website:
For more information about the benefits of paraquat in sustainable agriculture, click here.
It takes skill to no-till, but persevering and wider adoption could bring many benefits, says an article on ‘No-Till: the Quiet Revolution’ in a recent edition of Scientific American. 
No-till is a way of growing crops without plowing. The authors, soil and sustainable farming experts David Huggins, USDA, and Prof. John Reganold (Washington State University) cite the introduction of paraquat as a milestone in agriculture which made no-till possible.
As a broad spectrum, non-selective herbicide, paraquat controls weeds without the need to bury them by ploughing. The problem with ploughing is that it causes soil erosion. Thanks to John Deere’s adaptation of the mouldboard plow in 1837 the North American prairies could then be cultivated. However, as cropping continued to expand and intensify, problems became all too obvious. Take the Palouse region in Washington State. By the 1970s, all topsoil had been totally eroded from 10% of the cropland and up to 75% had been lost from another 60% of fields.
Soybean stands out from other major crops: broad leaved rather than a grass; a legume, so plants supply their own needs for nitrogen fertilizer while increasing the fertility of the land; soybeans are rich in oil, protein and carbohydrate; and the crop has been highly developed by plant breeders and agronomists. This makes soybean arguably the world’s most versatile crop.
With such a broad nutritional base, soybeans are a staple food and animal feed. Whole beans provide flours; soya oil is used in cooking and food; protein-rich soya meal left after oil extraction is an important livestock feed; and soya protein is used in drinks, baby food, noodles, and as a meat and dairy substitute.
A significant amount of soybean production in the US, in particular, now goes to make biodiesel (5 to 10% each year). Biodiesel is not soya’s first connection with motor vehicles. In 1941, Henry Ford’s enthusiasm for finding industrial uses for crops resulted in the manufacture of the ‘Biological Car’ made for an exhibition. The vehicle’s entire bodywork was made from plastic derived from soybeans!
Paraquat is an essential tool for soybean farmers
Soybeans stand out from other major crops: broad leaved rather than a grass; a legume, so plants supply their own needs for nitrogen fertilizer while increasing the fertility of the land; and soybeans are rich in oil, protein and carbohydrate.
In the US, soybeans are grown on half of the 30 million hectares on which no-till farming is practiced. In Brazil, no-till has also been widely adopted for soybeans. Broad-spectrum herbicides, led by the introduction of paraquat in the 1960s, allowed the adoption and growth of no-till which does not rely on controlling weeds by burial from ploughing.
Soybean fact file 111 million hectares grown worldwide in 2013
90% or more of all soybean fields in USA and Argentina are GM
70% increase in productivity since 2000
40% of bean weight is oil rich in monounsaturated oleic acid
12% of US soybeans were used to make biodiesel in 2014
13 million hectares under no-till in USA
No-till systems save cash, time and fuel, improve soil structure, reduce erosion and provide havens for wildlife. Paraquat is deactivated on contact with the soil meaning that it can be sprayed to burndown weeds before planting without risking crop damage from root uptake. Paraquat works well even in cold and rainy weather.
Maize, often called corn, along with wheat and rice is one of the world’s top crops. Maize provides basic staple foods for much of the world’s population. All around the world maize grain is a basic livestock feed, and the crop can be cut while still green to make silage as a winter feed. Also, increasing amounts of maize in the US are being used to make bioethanol fuel.
Maize, perhaps more than any other crop, reaches both high and low extremes of sophistication, mechanisation and technology in crop production. But, all farmers need to maximise the yield and quality of their produce, while saving the costs, time and labor needed to grow it.
Broad-spectrum herbicides, led by the introduction of paraquat in the 1960’s, have allowed the adoption and growth of soil cultivation systems which do not rely on controlling weeds by burial from ploughing.
Cotton is a fibre which protects the seed of the cotton plant, much as the flesh of an apple protects the pips.
In 1997, GM cotton tolerant to the non-selective herbicide glyphosate was introduced. Although herbicide tolerant cotton has many advantages, it has contributed to enormous increases in the use of glyphosate which is now posing problems by encouraging the development of resistant weeds which are no longer controlled by this herbicide.
No more than two applications of glyphosate should be applied to any one field over two seasons. Paraquat can provide the alternative means of effective and sustainable weed control.
Using paraquat in weed control programmes can also address a number of environmental issues concerned with cotton growing including soil erosion and degradation, water contamination by run-off and leaching of agrochemicals, and loss of habitats and effects on biodiversity.
Paraquat is deactivated on contact with the soil meaning that it can be sprayed to burndown weeds before planting a cotton crop without risking damage to that crop or indeed subsequent crops in the rotation. It does not pollute soil or surface waters because it is immobilised and deactivated immediately on contact with soil.
Citrus fruit make-up a vast family including not only oranges, lemons, limes and grapefruit, but also calamondins, citrons, pomelos and ugli fruit.
Integrated pest management (IPM) systems have been introduced to minimize the impact of citrus growing on soil, water, air and biodiversity.  Paraquat has a key role in sustainable citrus production by controlling weeds that would otherwise seriously reduce productivity.  It can be used in conjunction with other techniques to manage soil erosion, particularly the use of strips of grass or legume cover crops between trees.
Paraquat can be safely sprayed to manage the weed flora along the crop rows between the grass or legume strips without fear of damaging the citrus trees.  Paraquat is immobile in soil and cannot move to the roots and up into the shoots.  Tree bark cannot be penetrated by paraquat meaning that it can be sprayed right up to the base of the trees.  Even if paraquat drifts onto citrus leaves there is little or no damage because paraquat does not move through plants like glyphosate does.
Citrus fact file 1:  Brazil is the leading citrus growing country
8.7 million ha of citrus are grown worldwide
43% are oranges, 27% mandarin types, 11% lemons and limes, 3% grapefruit
33% of crops are grown for juice
Pull on a pair of jeans and literally enjoy the fruits of one of the world’s major crops and two industrial revolutions. The demin in jeans is a weave of cotton, originally ‘de Nimes’ in France.
Cotton is a fibre which protects the seed of the cotton plant, much as the flesh of an apple protects the pips. So, fruit are not only for eating.
In late 18th century England, James Hargreaves’s ‘spinning jenny’ led developments in cotton spinning technology for the textile industry and primed the Industrial Revolution, leading to factories and mass production.
Now cotton is a crop at the forefront of the revolution in biotechnology, being the second genetically modified (GM) crop to be introduced in broadacre agriculture after soybeans, in 1997. One of the main traits in GM cotton is tolerance to applications of the non-selective herbicide glyphosate. Other GM cotton varieties provide protection against some of the many insects which can ravage the crop. The choice of herbicide resistance as an early target for biotechnology research indicates the importance of effective weed control in cotton.