The aim of this three and half year (2007-2010) project in Cambodia is to increase the range of crops grown under rainfed lowland conditions by promoting non-rice crop technologies that provide efficient water use and high financial return to the growers. This aim can be achieved by adding a non-rice crop after the main wet season rice crop (i.e. rice/non-rice double cropping) and the key research issue is water - how to select the appropriate soil and water environment in the wet season for the following non-rice crop and how to ensure adequate water for it. The project will measure the available water and examine a range of management options for growing non-rice crops such as peanut, soybean, and mungbean.

The objectives of the project are:

(i) To develop profitable double cropping options for a rice/ non-rice (mungbean, soybean and peanut ) system for the rainfed lowlands in three provinces.

(ii) To define the water requirements for non-rice crops, determine the best use of small amounts of stored water, incorporate water use into available lowland models and predict the level of risk under mainly rainfed conditions of the diversified cropping systems.

The intended target group of the project is for small scale lowland rice farmers with favourable water availability on-farm. Limited amount of water may be available from underground or on-farm pond as supplementary irrigation to non-rice crops.

The project has almost identical activities in three major lowland rice growing provinces of Kampong Thom, Kampong Cham and Takeo. A few Districts were selected for each Province and farmers and collaborators from Provincial and District offices participated for activities to achieve Objectives 1-2. The project examines potential non-rice technologies in rice-based lowlands, and aims to develop agronomic packages for non-rice crops in lowlands. Assessment of cropping risks and economic evaluation of new technologies are two key aspects of the project.

The project commenced several months after the official commencement date of 1 April 2007. An UQ agronomist has been stationed at the Cambodian Agricultural Research and Development Institute (CARDI), Phnom Penh.

For the 2007/2008 period, one of the major activities for Objective 1 (Development of profitable double cropping systems) was testing of a number of soil types that are potentially suitable for legume crop production across three Provinces. Eleven experiments were conducted to test 4 different soil types and the three legume crops, each crop with two varieties. The soil types were Prateah Lang, Prey Khmer, Bakan and Toul Samrong, which are all common lowland soils in the Provinces. This series of experiments was successfully completed with several key observations. They are; importance of sowing at optimum time, requirements of furrow and bed planting for some soils, potentially large impacts of insect pests and diseases, and importance of providing sufficient amount of irrigation water to maintain optimum crop growth. Some, if not all, of these issues are strongly connected to labour availability and costs of appropriate field maintenance. As this series is the first attempt for the project to grow legumes after rice in lowlands in Cambodia, the findings and experience achieved here will assist development of project's future experimental and economic programs.

In addition, two model farms have been developed with farmer owners; one in Kampong Thom and the other Takeo. The main attribute considered here is the use of pond water to irrigate non-rice crops in lowland after rice harvesting. It is clear from the development and operation of the model farms that a major challenge facing these farmers is to secure an adequate quantity of water required for crop production with a minimum cost.

Another major activity for the Objective 1 was to assemble varieties of mungbean and soybean that were available in the country. This was achieved in 2007, and 28 varieties/advanced lines of mungbean and 29 varieties/advanced lines of soybean together with two peanuts varieties were tested for their performance at CARDI in 2007/08 dry season. Peanuts showed better adaptation to the poorly structured Prateah Lang soil at the field site, as was also observed in the soil type experiments mentioned earlier.

Objective 2 (Water requirements of non-rice crops and prediction of cropping risks) was achieved in conjunction with activities for Objective 1. It appears that the amount of water applied to the legume crops in some experiments was not adequate for achievement of maximum yields. This may be possibly due to the participating farmers and District Agriculture Office collaborators not being aware of the amount of water required for maximum yield, but also the cost of irrigation was high resulting in reduced irrigation frequency and amount.

The aim of this three and half year (2007-2010) project in Cambodia is to increase the range of crops grown under rainfed lowland conditions by promoting non-rice crop technologies that provide efficient water use and high financial return to the growers. This aim can be achieved by adding a non-rice crop after the main wet season rice crop (i.e. rice/non-rice double cropping) and the key research issue is water - how to select the appropriate soil and water environment in the wet season for the following non-rice crop, particularly peanut, soybean, and mungbean and how to ensure adequate water for it. The intended target group of the project is for small scale lowland rice farmers with favourable water availability on-farm. Limited amount of water may be available from underground or on-farm pond as supplementary irrigation to non-rice crops. Assessment of cropping risks and economic evaluation of new technologies are two key aspects of the project.
The project has almost identical activities in three major lowland rice growing provinces of Kampong Thom, Kampong Cham and Takeo. A few Districts were selected for each Province and farmers and collaborators from Provincial and District offices participated for activities to achieve project objectives. An UQ agronomist was stationed at the Cambodian Agricultural Research and Development Institute (CARDI), Phnom Penh for the whole reporting period.
One of the major activities for Objective 1 (Development of profitable double cropping systems) was testing of a number of soil types and legume species that were potentially suitable for legume crop production after rice in lowland across three Provinces. Eleven experiments were conducted in 2007/08 dry season to test 4 different soil types and the three legume crops, each crop with two varieties. The soil types were Prateah Lang, Prey Khmer, Bakan and Toul Samrong, which are all common lowland soils in the Provinces. This series of experiments was successfully completed in May 2008 and several conclusions were drawn; Prey Khmer soil is most suitable for legume crops after rice in lowlands (eg, 1075- 1244 kg/ha for peanuts). Crop yield varied greatly in Prateah Lang soil (eg, 47-1160 kg/ha for mungbean), which is the most common soil type in lowlands of Cambodia. Peanuts is most suitable in terms of crop vigour and yield among the three crops examined followed by mungbean. Crop yield was generally low but there were also several key observations that would help increase yield. They were; importance of sowing at optimum time, adverse effect of low soil fertility, requirements of furrow and bed planting for some soils, potentially large impacts of insect pests and diseases, and importance of providing sufficient amount of irrigation water to maintain optimum crop growth. Some of these issues are strongly connected to labour availability and costs of appropriate field maintenance. These observations were utilized in developing a series of experiments that were conducted in the 2008/09 dry season. Preliminary results of the second year experiments indicate yield was generally higher than the first year, and some treatments, such as mulching, helped increase yield, but data need to be analysed fully before firm conclusions can be drawn.
In addition to the experimental series, two activities of significance were conducted in the reporting period. One is continuous development of the two model farms that had been developed in the first year with farmer owners; one in Kampong Thom and the other Takeo. The third one is being developed in Kampong Cham. A major achievement so far is the demonstration of feasibility of double cropping (rice-legume in Kampong Thom) and triple cropping (rice-rice-legume in Takeo) using only supplementary irrigation water, and mostly by hand watering. Most of cropping areas of the farms were used to demonstrate the feasibility, although the legume crops (mungbean and peanuts) suffered some water stress and yield could be reduced to some extent. When the dry season legume yields become available, on-farm input and output analysis will be conducted.
The other major non-experimental activity during the period was conducting survey and workshops for farmers in the target area in Kampong Thom. The results of survey and workshops suggest the following points for the project; it would be useful to grow legumes in paddies adjacent to village or housing areas because they tend to be more accessible for supplementary irrigation and inputs of organic materials and also the crops can be protected from free grazing cattle and perhaps thief. Cultivating method specially land preparation should be selected to maintain soil moisture, and no tillage and mulching technique based on existing rice stubble may be useful. Farm or non-farm job opportunity and hence availability of family labour should be considered for successful adoption of the legume crops in lowlands.

The aim of this three and half year (2007-2010) project in Cambodia is to increase the range of crops grown under rainfed lowland conditions by promoting non-rice crop technologies that provide efficient water use and high financial return to the growers. This aim can possibly be achieved by adding a non-rice crop after the main wet season rice crop (i.e. rice/non-rice double cropping) and the key research issue is water - how to select the appropriate soil and water environment in the wet season for the following non-rice crop, particularly peanut, soybean, and mungbean, and how to ensure adequate water for the crop? The intended target group of the project is for small scale lowland rice farmers with favourable water availability on-farm. Limited amounts of water may be available from underground or on-farm ponds, as supplementary irrigation to non-rice crops. Assessment of cropping risks and economic evaluation of new technologies are two key aspects of the project.
In the first 2 years, the project had almost identical activities in three major lowland rice growing provinces of Kampong Thom, Kampong Cham and Takeo, but we have dropped Kampong Cham to concentrate on the two most appropriate Provinces in the reporting period. A few Districts were selected for each Province and farmers and collaborators from Provincial and District offices participated in activities to achieve project objectives. An UQ agronomist was stationed at the Cambodian Agricultural Research and Development Institute (CARDI), Phnom Penh for the whole reporting period.
In the first year (2007/08 dry season), we identified that Prey Khmer soil was most suitable for legume crops after rice in lowlands, followed by Prateah Lang soil, which is the most common soil type in lowlands of Cambodia. We also found that peanuts followed by mungbean were the most suitable in terms of crop vigour and yield among the three crops examined. We also noted a number of constraints for achieving high legume yield including: adverse effect of low soil fertility; requirements of furrow and bed planting for some soils; potentially large impacts of insect pests and diseases; and difficulty in providing sufficient amount of irrigation water to maintain optimum crop growth. Some of these issues are strongly connected to labour availability and also cost of appropriate field maintenance. These observations were utilized in developing a series of experiments that were conducted in the 2008/09 dry season to determine best options for legume growing in terms of irrigation water requirement, effect of mulch, time of planting and use of fertilizer and soil amendment. The main points to come from these experiments were the strong effect of straw mulch and the importance of adequate water supply without providing excess water to the crop. We also maintained two model farms that had been developed in the first year with farmer owners; one in Kampong Thom and the other Takeo. We have made economic analysis of model farm activities. Another area of economic analysis conducted is cost-benefit analysis of legume cropping after rice in lowlands. The analysis clearly indicated the adverse effect of labour cost on profitability of growing legume crops, particularly for watering by hand which is common in the area.
From the results of experiments and economic analyses, we developed the best bet technologies for growing mungbean and peanuts. The documents describing them were distributed and discussed with PDA officers in Takeo and Kampong Thom. In 2009/10 dry season, these PDA established 20 demonstration farms where mungbean, peanuts as well as tomatoes were grown as per our best bet technologies. While we have not received complete yield data set, some farmers appear to be producing very good crops of mungbean and peanuts. We also had a field day at Takeo where our model farm, experiments on irrigation frequency and mulch levels and demonstration of drill planted legumes were inspected by some 100 people (mostly farmers). Some commune chiefs were also invited from other areas and they showed strong interest in participating in the project in the future. Another field day was held in Kampong Thom.
In the 2009/10 dry season, we conducted experiments in 2 Provinces (Takeo and Kampong Thom) and at CARDI. The main aspects were to examine the effect of different quantities of straw mulch, plant density and bed configuration, and frequency and quantity of irrigation water application for both mungbean and peanuts.
We have also made selections among lines of mungbean, soybean and peanuts in 2008/09 dry season, and some selected lines of mungbean entered into replicated yield trials at CARDI in 2009/10 dry season.