Paraquat supports no-tillage systems in Sichuan

An October 9, 2006 article entitled “The Story of Gramoxone and No-tillage in Sichuan” (in Mandarin) appeared in the SanNong Online. Written by Chen Hongbo, the article details the process through which local Sichuan farmers discovered and achieved success with no-till farming systems with the aid of paraquat.

The adoption of no-till farming methods using paraquat has enabled farmers in this province to significantly reduce costs, labor and precious water resources while enabling them to increase yields and rotate crops even during the difficult rainy season – resulting in increased income.

Paraquat Supports No-Tillage Systems in Sichuan, China

Sichuan enjoys a unique climate due to the region's uncommon and varied topography and the influence of alternating weather patterns. In winter, Sichuan's climate is dry with little rainfall. Sichuan gets abundant rainfall from April to October, but in the west of the province, the rainy season is from May to September. This climate makes it difficult to rotate crops by conventional methods. Conventional tillageDescription Full width tillage which disturbs all of the soil surface and is performed prior to and/or during planting. There is less than 15 percent residue cover after planting. Generally involves plowing or intensive (numerous) tillage trips. Weed control is accomplished with crop protection products and/or inter-row cultivation. Authoritative On-line References and Resources http://www.fao.org/News/2000/000501-e.htm A news item from FAO discussing the problems with plowing and the advantages of conservation agriculture. also leads to and reduces the filtering capacity of soil – it can also cause a delay in planting and yield loss.

With the help of paraquat in no-till cropping systems, farmers can manage crops more effectively and make sure they can plant and harvest in one single season.

The story of no-till and Paraquat

The farmers in Meishan county, Sichuan Province, did not know about sustainable agricultureDescription Management and conservation of the natural resource base and the use of technological and organizational change in a manner that ensures continued agricultural production from the land for present and future generations. Such practices conserve land, water, and plant and animal genetic resources. They are environmentally non-degrading, technically appropriate, economically viable, and socially acceptable. Sustainability rests on the principle that we must meet the needs of the present without compromising the ability of future generations to meet their own needs. Therefore, stewardship of both natural and human resources is of prime importance. Authoritative On-line References and Resources www.nal.usda.gov Information from the USDA's Alternative Agricultural Systems Information Center. until 1982. The grass-roots extension workers and farmers started to think of new cultivation methods as they faced the difficulties of plowing in the rainy season. After having noticed increased growth and yield of some crops on a non tilled ridge, they tried out a wheat rotation in a non-tilled field. This experiment was a great success in its first year and the trial was expanded the next year. Led by Lei Nongtian and Fang Shu’an, who are now vice head and vice director of the People’s Congress of Meishan County, the no-tillage project was approved by the local authority and Meishan county became a demonstration site for no-tillage in Sichuan.

In the late 1980’s when no-tillage techniques were expanding, weed control became a major obstacle to yield increases. Two weed control methods were available at that time: manual weeding and herbicides. As no appropriate herbicide was available, adverse cases emerged, eg poor selectivity, narrow weed spectrum, poor efficacy or unacceptably long residue effects.

The Sichuan Plant Protection Station and other agricultural research stations started to screen herbicides in order to find a solution. Financial and technical support were provided by Syngenta and the non-selectiveDescription A chemical product used for eliminating all types of weeds (annual and perennial grasses and broadleaved weeds). Authoritative On-line References and Resources http://www.weeds.iastate.edu/ An invaluable source of contemporary information about herbicides and weeds from Iowa State University. herbicide paraquat appeared to be the ideal choice in no-tillage. Several trials confirmed that paraquat had the following benefits: high efficacy, rainfastness, broad weed spectrum, deactivates after contact with soil (no residue in soil), safe for crop rotation, etc. The use of paraquat also allowed farmers to conduct timely cultivation and minimize the adverse effect of rain. Paraquat was then widely used in the rotation of oilseed rape and wheat with rice. Meanwhile, Syngenta (the leading manufacturer of paraquat) helped with the demonstration and expansion of no-tillage farming using paraquat. Cooperating with plant protection stations at different levels, Syngenta conducted training for farmers on how to use paraquat correctly in no-tillage by demonstration and technical support. Fang Shu’an, the former head of the Agriculture Bureau now the vice director of the People’s Congress of Dongpo District, Meishan City, thinks weed control was vital for no-tillage. Gramoxone, Gramoxone Plus and Preglone* were the ideal choice as they have unique features of rainfastness, broad weed spectrum, excellent efficacy, safe to the crops and no residue in the soil, which well suits the local climates. A folk song about no-tillage and paraquat was even created. It described the importance of paraquat in no-tillage and benefits to farmers.

From then on (since 1995), no-tillage techniques developed quickly in Sichuan as the main issue of weed control was solved. From 200,000 ha, the no-till area has increased to 840,000 ha today and expanded to other areas and crops (vegetable, taro, garlic, maize and beans).

Benefits of no-tillage systems

Local farmers underline 5 major areas of benefit:

1. Labor, time and cost savings, with increased yields
2. Easier cultivation in wet conditions and less soil compaction
3. Effective control of weeds and diseases
4. Increase in the level of organic matter and improved soil quality
5. Easy to use.

According to extension workers, no-tillage also favours:

• Precious water savings,
• Timely sowing of crops (rice transplanting can take place 7 to 10 days earlier in comparison with conventional methods)

A farmers’ income could be increased by RMB 60-70 (8-9 US $) due to yield increases and cost savings.

* Gramoxone, Gramoxone Plus and Preglone are brandnames of paraquat-based products.