Agriculture Reference
In-Depth Information
of Bogor. Figure 1 illustrates the geographical location of the studied sites
in west Java, Indonesia.
5.2.2 FIELD INVESTIGATIONS
Field investigations were conducted in March and September 2008 and
September 2009, and details of farming practices and chemical or organic
fertilizer application were obtained from interviews with conventional
and organic rice farmers. For organic rice production, farmers use a self-
produced organic fertilizer called “bochashi,” which is composed of 10%
rice bran, 20% rice chaff, and 70% cow manure (in volume). Nutrient
component of this organic fertilizer are 28.29% carbon, 0.35% nitrogen,
0.17% phosphorus, 2.31% potassium, 1.87% calcium, and 0.42% mag-
nesium (on a dry matter basis). Based on the interview data, the cost for
farming and amount of labor required for farming were calculated. The
prices of materials were also obtained through interviews with merchants.
Figure 2 illustrates the difference between conventional and organic rice
production systems. We also interviewed about the true state of organic
rice production to workers.
5.2.3 SOIL AND CROP YIELD ANALYSIS
Organic fields were converted to organic from conventional farming after
August 2003, and we examined the 13th rice crop grown after the switch
to organic management. Organic fields did not receive the organic certifi-
cation. Conventional fields continued to be fertilized with chemical input
and no organic fertilizer. Both fields of organic and conventional rice pro-
duction were located in the same area.
Topsoil samples (from a depth of 0-10 cm) were taken from three con-
ventional and three organic rice fi elds in September 2008 with a 55.8 mm
diameter soil core sampler. Soil core volume was registered and water
content determined (gravimetrically) on sample aliquots, to calculate bulk
