Archive for the ‘fieldwork notes’ Category

India cabbage update

October 18, 2010

The cabbages planted in ARTI – India continue to grow well (06.10.2010). The difference in pots can be visibly seen, however differences between treatments will be determined by the measurements at the end of the crop cycle.

Cabbages 06.10.2010 India


Change to India biochar pot trials

August 27, 2010

The egg plants which were transplanted into the biochar amended pot treatments were removed since almost ¼ did not survive (disease). Instead cabbage will be used for the pot trials, which will also make monitoring the results easier. The harvest will be biomass, and only one value will need to be recorded, which will be on the same day when all the plants are uprooted. With crops like egg plant which have multiple harvest, a more intensive monitoring and recording method is required, and there becomes a level of uncertainty with the research interference as to at which time the fruit / vegetables are ready to be harvested. A total of 75 days should be required for this study.

Safety first!

August 2, 2010

Biochar was added to the last (for now…) rice field in the current trials, which is in Chireve village, close to Siem Reap. It is policy now to wear masks for biochar application just as a precautionary measure until more research is done on the potential risks when handling biochar.

Biochar spreading in Chireave 02.08.2010. Picture by Vichida Tan.

Rice progress from Harmony Farm

August 2, 2010

Since the rains seem to have arrived, a visit was made (29.07.2010), and the rice is growing well in Harmony farm (near Beng Mealea temple). Trials were set up with various amendments of carbonised rice husk (SME gasifier) and rice husk ash (brick factory) and the trial design includes controls. At present it appears that the rice with the biochar is a darker green and is growing particularly well. In the area with the highest amendment of brick ash, the rice is a more yellow colour.

Vannak and Sarah at the rice field 29.07.2010. Picture by Vichida Tan.

Planting in this farm was direct planting, 5 or 6 seeds being placed in each hole, spaced approximately 20-30cm.

Rice progress – 17.07.2010

July 22, 2010

Rice planted this season (usually planted between May and July), is wet season rice, irrigated through rainfall, although some farmers in this region have access to irrigation channels from the Barai (link to other post). Reportedly late rains have led to some difficulties for farmers in keeping their paddies flooded.

The plots with biochar added for the two farmers in Krable Riel were visited to see if there were any visible impacts for the addition of biochar. These had been planted at the beginning-middle of June. In one farmer’s field, there were more visible weeds in the plots amended with biochar. The farmer commented that once the field was flooded these will die off naturally, although he would also be doing some weeding of the field in the next few weeks. This demonstrates some of the impacts which biochar can bring to fields, a soil improvement which is a favourable environment for plant growth, although in this case weeds. It is hoped although was difficult to see, that the rice was growing better too.

In another farm with the same application of biochar, the rice appeared slightly yellower than in the areas which did not have biochar. No other changes were visible so it is hoped that this is not a problem.

Keep reading the blog for the final results at harvest (October onwards).

Weeds in farmer CADF3's rice field 17.07.2010

Rice growing timetable

June 25, 2010

Observations from the field were made on preparation and planting of rice in Pouk.

In this case a medium season rice is being grown – Phka Rumdoul. It has a medium duration (140-150days) and is being grown by out-growers in Kouk Cherei for the Nagathom fund.

First the grain is soaked for 24h.

Soaking rice, 24.06.2010 Kouk Cherei village

Then the grain is broadcasted by hand onto the nursery field, where it is grown for up to a month. This time often depends on the rains, since it is preferable to plant out in wet ground..

Broadcasting onto nursery field 23.06.2010. Kouk Cherei village.

Meanwhile the land is prepared and is ploughed up to 4+ times. We try to add biochar before the final plough to avoid ploughing dragging the biochar away from the plot too much.

Then finally the rice is planted out.

Lack of rain threatens rice trials

June 17, 2010

Rice trials were started at the Apsara research farm, however the farm relies almost entirely on the Barai, a large reservoir about 1km away for water. A extensive system of irrigation canals spans over more than one district and many farmers within this zone rely on this for crop irrigation.

T0 = control, T1 = 5t/ha compost, T2 = 5t/ha compost + 20t/ha biochar, T3 = 5t/ha compost + 40t/ha biochar.

Rice trials Tuk Vil, far plot T1, near plot T0. 17.06.2010

Rice trials Tuk Vil, far plot T3, near plot T4. 17.06.2010

The current Barai irrigation system was designed and built by the French in the 1930’s however agriculture based on irrigation has taken place in this region since the Angkor Empire in the 11th century. The reservoir has a storage capacity of 40 million m3 and serves an agricultural area of 12,000 ha which includes 4,000 ha served by the gravity distribution system through 50km of canals. The beneficiaries were estimated to be 5,465 households in 1990s (Barai references:

Changing weather patterns have been identified by many farmers who are involved in the trials whose agricultural calendar is ruled by the coming of the rainy season.

Biochar application physically alters soil

June 17, 2010

The third cycle of crops grown in the pot trials at the Apsara farm were harvested today. The lettuce were grown for 28 days in the pots, after a 14 day germination period in growing treys.

Biochar is reported to improve soil structure, as it can alter porosity, particle size, infiltration, drainage and water storage capacity. The physical impact of biochar in the pot trial soil was easily identifiable; it was much easier to remove the plant from the pot and the soil from the roots of the lettuce. A dense structure like that of the unammended pot will reduce the ability of the air and water to move through the soil and will make it more difficult for the plant roots to propagate through the soil.

The pictures show the two of the amendments, the soil clods are visible in the left hand picture (T0) which does not have any amendments. The picture in the right shows the biochar (84t/ha equivalent addition), compost and sediment amended soil.

Un-amended soil after lettuce harvest in pot trials. 17.06.2010

Biochar amended soil after lettuce harvest in pot trials. 17.06.2010

Cucumber crop failure

April 15, 2010

A visit to one of the cucumber farmers who has been testing of biochar on their farm found that pests and diseases had severely reduced the quality and quantity of the crop. This  trial cannot be included in the program, but harvests are still currently being recorded by two other cucumber farmers, so we are hoping some good results from the biochar trials there.


12/04/2010. Cucumber leaf with evidence of pests and diseases.