-Subsoil improvement for upland crop production in poor-drainage fields-
The National Agriculture and Food Research Organization (NARO), in collaboration with Hokkai KOKI, developed a subsoiler with characteristic wide V-shaped blades for breaking up compacted soil of the subsoil layer. It can be used by attaching to tractors and agricultural bulldozers. The "Cut Breaker" subsoiler can reach the deeper ground than the conventional subsoilers, up to a maximum of 70 cm depth from the surface. Soil compaction avoids surface runoff from being absorbed into the ground, causing a muddy field and wet damage. The "Cut Breaker" breaks up the compacted subsoil and improves soil condition, letting the surplus water to the ground and drainage pipes. Subsoil improvement using the "Cut Breaker" realizes better drainage leading to higher yield and stable crop production.
NARO has published a Standard Operation Procedure (SOP) for subsoil improvement using the "Cut Series" product line (including the "Cut Breaker"). It shows step-by-step instructions and other useful information that will support producers to improve their farmland condition. The SOP is available online on the NARO website.
Excess moisture in the soil often causes yield damage in growing crops and vegetables, and therefore well-drained soil condition in the fields is the basis for stable agricultural production. In Japan, rice consumption in the domestic market has been decreasing, and rice farmers are encouraged to convert their production from rice to other crops and vegetables. In the converted paddy fields with poor-drainage, subsoil improvement is an inevitable requirement, and there has been a strong demand for an effective soil improvement method. As a response, NARO, in collaboration with Hokkai KOKI, had released the "Cut Drain" and the "Cut Soiler" that are developed especially for easy and quick subsoil improvement by farmers to gain better drainage in the field.
The newly released "Cut Breaker" is a special subsoiler that can reach and break up deeper layers of compacted soil than the conventional subsoilers. It is a solution for fields with poor drainage caused by soil compaction. Attached to tractors or bulldozers, the single to triple V-shaped blades cut into the soil in the depth of between 30 ~ 70 cm and break up the hardpan soil. It creates up to three rows of crushed soil, in size of 10 cm-width on the bottom and a maximum of 80 cm-width on the top. The soil inside these rows has enough air permeability, and the texture is loose enough to let the water go into the underground. Improved soil condition promotes crop roots to grow and develop well, resulting in higher yield. The effect of the subsoil improvement using the "Cut Breaker" lasts for several years. Therefore, the treatment is appropriate for the fields with a long-term plan of growing crops other than rice.
The Standard Operation Procedure (SOP) for subsoil improvement using the "Cut Series" (the "Cut Drain", the "Cut Soiler", and the "Cut Breaker" equipment) is available online on the NARO website. Aside from step-by-step instructions, it also explains the mechanism, the expected results, and how this treatment contributes farmers to increase profitability. The SOP is expected to offer support for farmers implementing soil improvement using the "Cut Series" equipment.
Standard Operation Procedures (SOP) for subsoil improvement using "Cut series" (Only in Japanese)
Soil erosion countermeasures: A simple solution that farmers can implement as part of the farming practice (Press Release, 2020)
Fig.1 General information of the "Cut Breaker", and the soil improvement using the equipment
Photo 1 Effect of subsoil improvement using the "Cut Breaker" on the growth of soybean
Fig. 2 Change in penetration resistance after soil improvement using the "Cut Breaker"
Table 1 Effect of subsoil improvement using the "Cut Breaker" on yield increase
Table 2 Cost-effectiveness of soil improvement using the "Cut Breaker" to crop production