Biochar, is produced when biomass is heated in a closed container with little or no available air [1] . Its utilization in large scale in agriculture is expected to improve soil properties, as well as reduce greenhouse gas emissions such as carbon dioxide gas and methane gas [2] [3] [4] [5] .

Biochar types vary depending on the raw material, pyrolysis time and temperature [6] . Rice and bamboo are two typical crops in Asia Pacific region. While rice is the most important food crop and 90 percent of world’s rice is produced and consumed in this region [7] , bamboo is a major non-wood forest and wood substitute found in all regions of the world [8] . Rice husk is one product of rice production. It is the outermost layer of rice seed and it counts for around 20% of total rice production, equivalent to 154 million tons produced annually in Asian countries [9] . The problem here is to manage the rice husk production effectively not only for economic reasons but also to prevent the environmental pollution from burning it. Similarly to rice husk, bamboo area covers over 6.3 million km² in Asian countries [10] . It is known as an easy-growing plant and more than ten million farmers are involved with bamboo production, adding up to 35 million jobs [11] [12] . The rapid growth of bamboo forest tends to overpower other plant species and become a monoculture forest, contributing to the loss of biodiversity, soil nutrition, and damaging soil’s physical structure [11] [13] . Using rice husk and bamboo as biochar raw materials seems to be a good solution that not only helps to solve those environmental problems mentioned above, but also effectively uses the available material in Asia countries.

The tomato, one of the most popular vegetables grown in home gardens, requires little space for a large yield. It is relatively low in calories and is a good source of vitamins C and A that are loaded with many human health benefits. Among various tomato varieties, draft cherry tomato is a small sized one, with its fruits often used in salads. It is easy to grow even in pot conditions, is quite resistant to pests and diseases, and does not require staking.

Many previous papers have evaluated the effect of biochar on the physical and chemical properties as well as soil microorganisms [14] - [21] in terms of soil pH, bulk density, porosity, water retention, saturated hydraulic conductivity, available water content, nutrient absorption and release of nitrogen, phosphorus, potassium and the microorganisms into the soil. There are also numerous papers that identify the impact of biochar on growth, yield, and quality on crops such as rice, maize, soybean, pepper, etc. [22] [23] [24] [25] . However, there were few papers that compared the effect of rice husk and bamboo biochar, two available materials in Asian regions.

This study aimed to clarify the different expressions of draft cherry tomato growth, yield and especially quality under the effects of bamboo and rice husk biochar via exploring the soil physicochemical property changes occurring after biochar application after tomato cultivation, to get a firsthand account of whether bamboo biochar or rice husk biochar utilization was better.

Two types of biochar were used in this experiment, namely commercial rice husk biochar (RH) and Bamboo biochar that was pyrolysed at 500˚C for 1 hour (Figure 1). Biochar was crushed to ≤2 mm before being mixed with soil.

Soil was collected from the soil surface layer (up to 20 cm depth) from the field at Kyushu University Farm in Kasua-machi, Fukuoka, Japan. The soil was clay loamy, which contains 34% sand, 30% silt, and 36% clay. The soil was air dried and passed through a 2-mm stainless steel mesh sieve.

Biochar, soil pH, and electrical conductivity (EC) were measured by pH meter (HORIBA LAQUAtwin B-712) and a conductivity meter (HORIBA LAQUAtwin B-771) with 1:10 (w/v) suspension of biochar on deionized water. Bulk density of soil and biochar was calculated by the dry weight of soil and compact weight of biochar in 100 cm³ steel cylinder. The concentration of elemental C, H, N were examined using an elemental analyzer.

Compost used in this experiment was the fermentation type consisting of mixed bark with sludge; manure of chicken, cow and pig; and plant residue. It was produced by the Dainichi Giken Company, registration number 83201. Compost was mixed with soil at the rate 1:5 (weight/weight).

The experiment was set up at a glasshouse in Kaizuka field, Hakozaki campus, Kyushu University (33˚37'37.8''N; 130˚25'31.3''E). The two types of biochar were added to the pots at rates of 2% and 5% (biochar weight/soil weight). Hereafter the treatments will be named RH2, RH5, BB2, BB5; totalling 5 treatments in the experiment when counting the control without biochar amendment. Each treat-

ment was repeated 3 times and arranged in a randomized block design. Thus, there were 15 pots in this experiment. The pots were sized 12.5 cm × 18 cm × 20 cm (bottom × top × height) and filled by soil and biochar mixture to a height of 17 cm. Tomato (1 plant/pot) was sowed in on 15th March 2016, transplanted in a pot on the 20th April 2016, and harvested the 25th July. Seven grams of N: P: K (14:14:14) was added to each pot of tomato. The same irrigation was supplied among treatments. Some crop’s growth, yield and quality parameters including crop height (cm); biomass yield (g); number of fruit; fruit diameter (cm); fresh fruit weight (g); total glucose and fructose content (g/l); ascorbic acid content; and soil physicochemical properties including available water; total N, P, K were observed.

Chlorophyll content of leaf was measured by SPAD 502 Plus meter (A product of KONICA MINOLTA) in the morning at 9:00 am. The height of tomato at harvest time was measured by the length in cm from the soil surface to the top of crop; Number of leaf: total leaves that crop had during its life; The aboveground and underground fresh biomass yield were observed after harvesting; Fruit diameter (cm) was measured by caliper with the accuracy of 1/20 mm; Fresh yield (gram): the total fruit weight of all harvest times, tomatoes were harvested at red stage of the ripening color chart [26] ; tomatoes were stored in frozen conditions after harvest. Tomatoes from all harvest times then were extracted to analyze the quality. Total sugar and ascorbic acid contents were measured by RQflex plus 10 meter using test strips base on the procedure number 116,136 and 116,981, respectively, [27] [28] . For total sugar analysis, the extract solid sample was diluted 10 times, then the mixture of 10ml distilled water, 5 drops of reagent TS-1 and 1 ml of pretreated sample was measured by RQflex plus 10 meter.

Soil available water was measured by hanging column and centrifuge me- thods; soil total N, P, K were determined after wet digestion with salicylic-sul- furic acids and sodium thiosulphate. Then, total N analysis and total P were measured by Gilford 300N spectrophotometer at wavelength 625 nm and 710 nm, respectively; Total K was identified by using Polarized atomic absorption spectrophotometer.

The statistical differences among the treatments were clarified by analysis of va- riance (ANOVA) in combination with Fisher’s least significant difference (LSD) test. The difference among the value was considered statistically significant at p < 0.05. Data analysis was performed using SPSS 20.0 software.

Physicochemical properties of soil biochar and compost are listed in Table 1