Pesticide Risk Assessment in Rice Paddies: Theory and Practice

Ettore Capri, Dimitrios Karpouzas, Ettore Capri, Dimitrios Karpouzas

• Publisher: Elsevier Science
• Year: 2011
• ISBN:
  9780080551142
• Topic: Biological Sciences
• Subtopic: Environmental Science
• Index: Biological Sciences

Rice is cultivated throughout the world under submerged conditions. The high water requirements and the heavy pesticide load used in rice paddies worldwide have resulted in contamination of associated surface water, such as streams, ditches, rivers and lakes. The uniform risk assessment approach which has been developed for other crops is not applicable to rice paddies, because of the specific conditions applied to rice cultivation.
Pesticide Risk Assessment in Rice Paddies: Theory and Practice fills the gap in information on this subject. Written by experts, this book summarizes the methods used for pesticide risk assessment in rice paddies, the limitations and problems encountered and future developments. It also examines the various agronomic, pesticide application and risk assessment approaches used in different rice cultivated zones in Asia, America and Europe and is an essential reference for those working in this area.* The only up-to-date book dealing with pesticide risk assessment in the flooded conditions of rice paddies
* Offers guidelines on the use and application of existing modeling tools, specific for rice cultivation
* Presents the differences and similarities in rice cropping systems and how these relate to pesticide risk assessment

Chapter 1

Rice Cultivation in the E.U. Ecological Conditions and Agronomical Practices

Aldo Ferrero,

Antorsio Tinarelli , Dipartimento Agronomia, Selvicoltura e Gestione del Territorio, Universita, di Torino, Italy

Publisher Summary

This chapter discusses the rice cultivation in the EU ecological conditions and agronomical practices. The rice production originated from all these countries together accounts for more than three quarters of the total world production. Rice is grown in at least 114 countries with a total production of about 610 million metric tonnes. It has been estimated that rice has fed more people over a longer period than any other crop. One-half of the world population and virtually all of East and Southeast Asia are entirely dependent upon rice. The introduction of rice in the Mediterranean European countries has long been debated. This plant came first in the North African regions from the East through an unusual series of leaps and bounds, thanks to its incredible capacity to adapt itself to different and variable environmental conditions. In the European Union rice is at present cultivated in about 410,000 ha, mostly located in the Mediterranean countries. The top two rice producers that together contribute more than 80% of the total rice production in Europe are Italy and Spain. Rice is not a staple food for most of the European population; nevertheless, rice consumption in the continent has increased in the last few years due to immigration and diversification of the diet of the Europeans.

Contents

1. Introduction

2. Rice ecosystems

3. Rice cultivation in Europe

4. Ecological conditions

5. Agronomic practices

5.1. Soil preparation

5.2. Seeding

5.3. Crop rotation

5.4. Irrigation and water management in the rice field

5.5. Fertilization

6. Weeds and weed management

7. Rice diseases

8. Invertebrate pests

9. Ripening and harvesting

10. Paddy drying process and product preservation

11. Crop management and environment

References

1 INTRODUCTION

Rice, after wheat, is the second largest cereal crop and the most widely consumed staple food grain. Globally, rice occupies about 145 million ha, a surface which constitutes one-tenth of the arable land, while in the majority of Asian countries, it comprises one-third or more of the planted area (FAOSTAT, 2006). India, China, Indonesia, Bangladesh, Vietnam and Thailand are the largest rice producing countries. The rice production originated from all these countries together accounts for more than three quarters of the total world production. Rice is grown in at least 114 countries with a total production of about 610 million metric tonnes (FAOSTAT, 2006). It has been estimated that rice has fed more people over a longer period than any other crop. Even now, one-half of the world population and virtually all of East and Southeast Asia is entirely dependent upon rice. In Bangladesh, Myanmar and Vietnam, for instance, the annual rice consumption per person ranges from 150 to 200 kg and accounts for most caloric and protein intake (Maclean et al., 2002). Some hundred millions of small farmers and landless workers derive their income from rice production. In most Asian countries, rice cultivation provides main employment to the majority of people, as it requires up to 250 person-days per hectare.

Rice shows an incredible capacity to adapt itself to a great variety of soil and climatic conditions. It is cultivated in areas such as those in the Upper Sind in Pakistan, where during the rice season temperature averages 33°C, or in temperate climate areas, like those in Northern Italy, where the mean temperature during the growing season is about 18°C. Rice is grown under a wide range of water availability; in areas with mean annual rainfall of about 100 mm (Al Hasa Oasis in Saudi Arabia) to areas with mean annual rainfall of 5000 mm (Myanmar’s Arakan Coast). The crop is cultivated at very different altitudes, from the sea level, in river delta, to the Himalayan slopes of Nepal, at 2600 m (Ferrero, 2005).

After World War II, rice-cultivated surface increased by almost 70% and the total production roughly tripled. During this period of time, most traditional rice importing countries which faced severe rice security problems (e.g. India, Vietnam, Philippines) achieved self-sufficiency in rice. The greatest achievements were obtained mainly from the early 1960s, with the so-called Green Revolution, which led to the cultivation of new lands to rice or the shift into rice from other crops and to the introduction of higher-yielding varieties or increased cropping intensity.

Since 1990 the rice harvested area expanded with a pace of about 0.4% a year, and the average yield of the crop increased by about 2%. If this trend and the estimates of the Asian population growth rate are maintained over the next decades, rice production will fail to keep pace with population growth. In major rice producing and consuming countries in Asia, population is forecasted to grow more than 1% per year.

2 RICE ECOSYSTEMS

At present rice is grown in all continents under various environmental conditions, which according to IRRI can be separated into four main ecosystems including irrigated, rainfed lowland, upland and flood prone (Maclean et al., 2002) (Figure 1).

Fig. 1 Main rice ecosystems in the world.

The irrigated ecosystems account for about half of the world’s rice harvested area and provide 75% of total rice production. Irrigated rice covers most of the America, Australia and Europe cultivation area and a significant part of Asia and Africa. In relation to rainfall availability, irrigation ecosystems are divided into irrigated wet season and irrigated dry season systems. Irrigated wet season includes ecosystems where rice is grown during the wet season and irrigation water is provided with the purpose to supplement rainfall. Irrigated dry season is typical of the ecosystems where during rice cultivation rainfall is usually very low, and water is mostly provided by irrigation. These areas are characterized by a markedly high solar radiation and evapotranspiration, low pest incidence and high yield potential. Average paddy yield can vary from 4 to 10 t ha⁻¹ according to input levels that are adopted. Highest values are recorded in America, Australia and Europe where in most situations yield exceeds 8 t ha⁻¹, with only one cultivation in a year. Irrigated rice is grown in leveled and bunded fields, where irrigation water is maintained in a layer ranging from 2.5 to 15.0 cm depending on the availability of water. Rice is directly seeded or transplanted in puddled soil. Rice varieties that are suitable for irrigated ecosystems are usually short in size, highly responsive to N supply, resistant to many pests and with high yield potential. Constraints to sustainable rice production in irrigation ecosystems include losses from weeds, pest and diseases, inadequate water ...