Further identification of two agrometeorological services in Hebei province, China

By KEES STIGTER

Energy and essence are of utmost importance,
so make sure you keep them well and never lose them.
Never lose them, keep them inside

From Zhang Wei’s “The ancient ship”

FURTHER IDENTIFICATION OF TWO AGROMETEOROLOGICAL SERVICES IN HEBEI PROVINCE, CHINA

Kees Stigter1), Li Chunqiang 2), Zheng Dawei3), Wang Shili4), Ma Yuping5),

1) Agromet Vision, Bondowoso, Indonesia & Bruchem, The Netherlands (cjstigter@usa.net)

2) Hobei Provincial Meteorological Administration, Shijiazhuang, Hobei, China (chunql@sohu.com)

3) Department of Agrometeorology, China Agricultural University, Beijing, China (zhengdawei44@263.net)

4)Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing, China (wangsl@cams.cma.gov.cn)

5) Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing, China (mayp@cams.cma.gov.cn)

Introduction

The present project, core funded by the China Meteorological Administration (CMA), was prepared by the Asian Picnic Model Project (APMP, Agromet Vision) and China Agricultural University (CAU), Beijing, from 2004 till 2007 in several missions to five provinces. In the APMP, capacity building is the main issue and all preparations, all transfer of knowledge and all teaching takes initially place in the Asian country where the project is based. Approaches can be found in the literature quoted most recently in KNMI (2006, rev. 2008).

After an outing to the Longman caves with its many Buddhas, from Zhengzhou on Sunday, still in the first half of October we took an evening train to Shijiazhuang, Hebei Province, for a short last part of this leg. We first visited the fields with the plastic greenhouses (first case study here) in the morning and after that we visited a cave. The fields of the other case study, mulched wheat fields, we visited already several years ago.

The following day we got re-explained the two studies “CMA/CAU/APMP Agrometeorological Services Case Study IX” (in short CCAAS Case Study IX), with the title “Winter straw mulching increasing water use efficiency and yields in winter wheat” and “CMA/CAU/APMP Agrometeorological Services Case Study X” (in short CCAAS Case Study X), entitled “Early warning of low temperatures and less sunshine for plastic greenhouse crops in winter”. We complimented the presentation because it was fully done in English!

After that Stigter gave here the same lecture that he gave in Ningxia on “Institutionalization of extension to cope with natural disasters” as the fourth lecture given in the course of time here. He started again with past and present of this pilot project. There is now an operational group of four agrometeorologists in Shijiazhuang at Hebei’s Meteorological Administration /Bureau/Offices/Services. We had two earlier contributions from here to the INSAM contest on best examples of agrometeorological services (Li, 2007; 2008). This shows the impact of the preparations of the present pilot project phase in the previous years. Both submissions got honorary mentions.

Research work on this topic has been done at the China-Canada Agricultural Experimental Station, Dengzhuang, Hengshui, Hebei Province. The extension areas were also in Shenzhou and Fucheng counties of Hengshui, and in Yongnian county of Handan in Hebei Province. The extension services demonstrated the results, but drought is a complex problem affecting agriculture. The duration and severity of drought, especially the information as early warning and prediction of drought needs to be provided timely and in a suitable way to farmers for them to act.

Simple sunlight plastic greenhouses (with a thick solid wall and isolation material at the north side and bamboo or metal frames) developed quickly in China since the 1980s, improving agricultural production by adding winter crops. We visited an experimental greenhouse in Gaoyi County with very young furrow irrigated Cucumber plants, that were sprayed against fungus disease during our visit.

Bad weather in winter comes as too little sunshine, too strong cold, strong winds, the weight of snow cover. Last winter the conditions became so bad, with very much damage to such greenhouses, that the government provided ovens on a large scale to save what could be saved, but this is rare.

Winter straw mulching increasing water use efficiency and yields in winter wheat

Stigter (1994) already 15 years ago reviewed that eight factors may be distinguished that are affected by mulch application: soil temperature; soil moisture; other soil physical properties; soil erosion; weed growth and other pests as well as diseases; soil microbial and other microfloral and microfaunal activities; soil chemical properties; and aerial physical properties. There are indications from research carried out in Hebei Province that over the winter wheat growing season reference evapotranspiration is decreasing since 1965 due to climate change (Li et al., 2008).

As explained in Li (2007), the example was derived from the extension programme and operational service by the Agrometeorological Center of Hebei Province, in collaboration with the Chinese Academy of Meteorological Sciences (CAMS) and local weather stations, also including some research results from the Meteorological Institute of Hebei Province and CAMS. The farming system is irrigated or rainfed winter wheat cropping or corn-winter wheat cropping. For the latter: June to September for sole corn after the wheat has been harvested and October to June for sole wheat. At the beginning of winter, wheat is mulched with between 4.5 and 6 tons/ha of straw mulch.

By comparison with winter wheat with uncovered soil, it was shown that the soil water content of winter wheat mulched with corn straw was much better, especially before the wheat elongating stage in spring. It could enhance soil water in the top 60 cm by 1.3%, equivalent to 10mm of rainfall. The microclimate of wheat fields was changed evidently under straw mulching. According to field measurements, air temperature and turbulence near the surface increased, and air humidity and soil temperature decreased in mulched wheat fields. In winter soil temperatures increased under the mulch and the daily range decreased. In spring, soil temperature was for example from 0.1 till 0.7 °C lower at 20 cm depth under mulch. Looking at the energy balance, mulching caused an increase of sensible heat flux and a decrease of latent heat flux, so the soil evaporation from mulched wheat fields was reduced and the transpiration of wheat was increased after the elongation stage.

The total evapotranspiration may not have increased; it only changed the water consumption in time and way. In winter (mulched period), soil evaporation decreased and soil water increased; after the elongation stage, wheat transpiration increased. The water for soil evaporation was converted to wheat transpiration through mulching wheat in winter times.

Although “CCAAS Case Study IX”, in the categorization used earlier in Stigter’s (2008a) Hyderabad Souvenir Paper and his recent draft WMO brochure (Stigter, 2008b), definitely is an example of “Advices such as in design rules on above and below ground microclimate management or manipulation (B)”, also here the increase of water use efficiency is more important than the yield increase obtained. Therefore it is also an example again of “Proposing means of direct agrometeorological assistance to management of natural resources (J)” for the resource of “water”, like in the “CCAAS Case Study VII” of Henan.

The importance of the service of advising on mulching has grown because of a generally found increase of temperature (particularly of minimum temperatures) and decrease of precipitation since the 1990s (with something as 20 mm in Hebei province), with frequently occurring drought periods in this monsoon type climate with rain falling in summer. Water requirements may therefore have increased, the decrease in reference evapotranspiration not withstanding (Stigter, 2008c).

Wheat yields under mulching increased by 5%, but more importantly the water use efficiency increased with 12 to 16% under an initial irrigation and subsequently rainfed conditions afterwards. This confirms the lesson learned from the Henan soil moisture services provided.

Early warning of low temperatures and less sunshine for plastic greenhouse crops in winter

The use of plasticulture in the production of horticultural crops (vegetables, small fruits, flowers, tree fruits, and ornamentals) helps to mitigate the sometimes extreme fluctuations in weather, especially temperature, rainfall and wind. Many growers experience some extremes in weather conditions during the growing season that can kill or injure the crops, or reduce marketable yield. Row covers, low tunnels and high tunnels all have the potential to minimize the effect of these extreme weather events on the crop and optimize plant growth and development in a protected environment. Plasticulture is a technical reality. Such production systems are extending the growing seasons in many regions of the world. They encourage conservation and preservation of the environment rather than the exploitation of the land and water (Stigter, 2008d).

The thermal environment is of course affected by the plastic but the production technology also leads to humidity increases that may produce vegetable diseases from fungi. Opening reduces the absolute humidity as well as the temperature, to which the growth will then adapt. Of course with less sunshine, the temperatures are lower and when the weather improves the climate gets restored.

Under conditions of low sunshine and at night, the plastic is covered with matting or bound straw to prevent too high reductions of temperatures in the greenhouses. So manipulation of cover over the plastic is an intrinsic part of regulating the greenhouse climate.

As to “CCAAS Case Study X”, the same applies as to “CCAAS Case Study IX”, because it belongs, in the categorization used earlier in Stigter’s (2008a) Hyderabad Souvenir Paper and his recent draft WMO brochure (Stigter, 2008b), to Category B in principle but the natural resources “solar radiation”, “heat” and “CO2” are managed here also with agrometeorological assistance into use that otherwise would not be possible (Category J), assisted by a specifically geared medium range weather forecasting for early warning.

In “CCAAS Case Study X”, we have to do with such an early warning of low temperatures and low sunshine duration (only 3 hours or less per day) over periods longer than two days at some crop stages and longer than a higher number of days at other crop stages.

Light (in the meaning of relatively small) losses from any source are defined as less than 30% in final yields, medium losses as 31 till 70% and heavy losses as more than 70%. For example light losses occur in Cucumber when periods with 3 or less hours of sunshine per day occur for 3 to 6 days at the seedling stage, for 7 to 10 days before flowering and again for 3 to 6 days after flowering.

Information dissemination of this service of the forecasting of days with less than 3 hours of sunshine and some weather disasters, including low temperatures, is to the government and the farmers through weather forecasts. So, finally there is the lesson, from Hebei and more generally, of the importance of simply using existing and improved general - and of course where possible special - weather forecasts and short range climate forecasts explicitly for providing the required information as an agrometeorological service.

This is very much in line with Prof. Murthy’s pleas from his work at ANGRAU in Hyderabad (Murthy, 2008; Stigter, 2008b), where published newspaper weather forecasts are used with farmers. In China, this can be by radio and TV, SMS messages on mobile phones, telephone information that can be obtained at special numbers, printed forms of some of the information and via the internet with separate weather and agricultural sites. A rough estimation is that in Hebei presently 50% of the yield losses are prevented by the information given in the agrometeorological service.

Acknowledgements

The preliminary account given in the information sheet above has largely been derived from a first part of a draft of Prof. Stigter’s recent mission report (Stigter, 2008c) on his September/October mission to China. Using the English language, in which most of the co-authors are not or less conversant, while he is not conversant with the Chinese language, any errors are his responsibility. Prof. Zheng Dawei is the skilled intermediate and translator for Stigter’s work in China since 1999. The Chinese Meteorological Administration (Beijing) is acknowledged for the core funding of the present pilot project. The Provincial Meteorological Administrations concerned are thankfully mentioned for their organizational efforts to make the more detailed identification of these agrometeorological services possible. Their great hospitality made the tiring travel more than worthwhile.

References

KNMI for Netherlands Government (compiled by Kees Stigter), 2006 (Rev. 2008). Capacity building in the area of agrometeorological services through roving seminars. Document originally distributed and presented as CAgM-XIV/INF. 4 at the XIVth Session of the WMO CAgM, New Delhi, October/November.

Li, Chunqiang, 2007. Straw mulching combating drought in winter wheat. Available at the INSAM website (www.agrometeorology.org) under Accounts of Operational Agrometeorology of May 2007.

Li, Chunqiang, 2008. Furrow planting and ridge covering with plastic film for drought relief of crop growth in semi-arid regions. Available at the INSAM website (www.agrometeorology.org) under Accounts of Operational Agrometeorology of April 2008.

Li Chunqiang, Li Baoguo and Hong Keqin, 2008. Analysis of the temporal-spatial variation for reference crop evapotranspiration in Hebei Province. Paper presented at the International Conference on Biometeorology, Tokyo (Clim Variat-O06).

Murthy, V.R.K., 2008. Report on the project entitled “WMO-ANGRAU-DST sponsored Roving Seminars on Weather, Climate and Farmers”. Available at the INSAM website (www.agrometeorology.org) under “Needs for agrometeorological solutions to farming problems” of February 2008.

Stigter, C.J., 1994. Management and manipulation of microclimate.Ch. XXVII in: J.F. Griffiths (Ed.), Handbook of Agricultural Meteorology, Oxford University Press, (pp. 273 – 284).

Stigter, Kees, 2008a. Operational agrometeorology: problems and perspectives.

Invited contribution (Souvenir Paper) to a Souvenir Booklet for an International Meeting on Agrometeorology and Food Security. CRIDA, Hyderabad, India, pp. 41 – 47.

Stigter, Kees, 2008b. Agrometeorological services: reaching all farmers with operational information products in new educational commitments. Draft brochure written for WMO/CAgM, 26 pp.

Stigter, Kees, 2008c. Report of a fourth "Agromet Vision" mission to Asia: China, Indonesia, 15 September 2008 till 30 April 2009. First part on China. Agromet Vision, Bondowoso (Indonesia) and Bruchem (Netherlands), 28 pp.

Stigter, Kees, 2008d. Problems and solutions in coping with extreme meteorological events in agricultural production, and challenges remaining for the use of science to contribute to problem analyses and designing valuable solutions in this context: cropping under cover. Draft section III.4.3. (A) in: Kees Stigter (Ed.), Applied Agrometeorology. Springer, Heidelberg/Berlin/New York, in preparation for 2009.