Farm Yard Manure Biochar for Sustainable Cassava Production
in the Degraded Lands of East Java, Indonesia
Titiek Islami 1), Bambang Guritno2), Wani Hadi Utomo3)
1)
2)
3)
Department of Agronomy, Brawijaya University, Malang Indonesia
Research Centre for Root and Tuber Crops, Brawijaya University, Malang, Indonesia.
International Research Centre for Management of Degraded and Mine Land; Brawijaya
University, Malang, Indonesia
Extended abstract.
It is a common phenomena soil fertility status of land planted with cassava decreased
continuously, either due to high erosion rate, high nutrient uptake, and decreasing of
soil organic matter. The traditional method to overcome this problem is applying
organic manure to the soil. Due to the rapid decomposition of organic manure in the
soil, the addition of organic manure should be done at every planting season.
Application of organic manure should be done in a high dosage; therefore the yearly
application of organic manure is often uneconomically. In addition, it is suggested
that CO2 released from these decomposition has a high contribution to global
warming. It is suggested to use more recalcitrant organic material sources, such as
biochar to obtain a sustainable cassava production.
To test that hypothesis three year research was done at Wringinrejo, Blitar. Indonesia..
Five treatment of (i) No organic manure; (ii) Farm Yard Manure applied once at the
staring of the experiment; (iii) FYM applied every planting season; (iv) biochar made
from FYM applied once; and (v) biochar made from cassava stem were arranged in a
Randomized block design with 4 replication. Biochar was made by a simple method
as described in Sukartono et al. (2011). The data collected include dry biomass, crop
yield and soil fertility status (sol organic matter, total nitrogen, available P and
available K).
The experimental results show that application of FYM, biochar made from FYM and
biochar made from cassava stem increases cassava growth and yield. The first year
yield of cassava without organic manure was 24.67 Mg/ha, where as the yield of
cassava applied with FYM, FYM biochar and cassava stem biochar were 29.48
Mg/ha, 32.64Mg/ha, and 25.37 Mg/ha respectively. The associated above ground dry
matter were 6.04 Mg/ha (No OM), 7.95 Mg/ha (FYM), 9.47 Mg/ha (biochar FYM),
and 7.67 Mg/ha (cassava stem biochar). Planting cassava continuously on the soil
without OM application soil and soil applied with FYM once at the beginning of
experiment decreased cassava yield. The first year yield of cassava without organic
manure was 24.67 Mg/ha decreased to 18.26 Mg/ha for the second year yield and
further decreased to 14.85 Mg/ha for the third year yield. The yield of cassava applied
with FYM (once) was 29.48 Mg/ha (first year), 31.55 Mg/ha (second year), and 23.42
Mg/ha (third year). The application of FYM at every planting season was not only
stabilized, but there was a tendency of increased the cassava yield. Until three year of
planting cassava, application of FYM biochar and cassava stem biochar.
Planting cassava continuously on the same soil, even with in-organic fertilizers
application decreased soil fertility status, especially soil organic matter and Nitrogen
content. The same phenomenon if FYM was only applied once at the beginning of the
experiment. Application of FYM at every planting season could buildup soil organic
matter and soil nitrogen content. Application of FYM biochar and cassava stem
biochar increased soil organic matter and it was relatively stable until 3 years after of
application. Application of cassava stem biochar increased available potassium, but
at the third year after application available potassium in this applied soil was not
different from the other treatments.
Key words: sustainable production, soil organic matter, agrichar