SEMNAS Hortikultura Buku 2 - Departemen Pertanian

Application of Chemical and Bio-Fertilizers in Relation to String Bean (Phaseolus vulgaris L.) Yield and Soil-Borne
Pathogen
Mulyadi, Pustika, A. B. and Iswadi, A
more determined by the ability of the soil to supply nutrient to the root than whether the ability of
crop root to absorb nutrient or nutrient uptake kinetics of the crop root (Barber, 1985). Among the
essential nutrient elements, nitrogen (N), phosphorus (P), and potassium (K) are required in large
amount by crops, however; the natural nutrient supply of most soil are often unable to meet the
nutrient need of crop for high yield. Some of the limiting factors related to the soil nutrient supply,
among others; naturally, soil is poor in nutrients or the soil contain high nutrients but a large part of
the nutrients in relative slow or difficult available forms due to they are fixated by clay minerals or
still as constituents of either organic matter or primary minerals. Besides that, the soil nutrient
availability can also loss from root zone due to leaching process by percolation water, volatilization,
and brought by erosion (Tisdale et al., 1993; Plaster, 1997). Hence, adding external N, P, and K to the
soil through fertilization are important in attempting to increase and sustain crop production. In
addition, the use of fertilizer that more eficient and no negative impact to the environment should be
paid attention in developing fertilization technology.
To date, for the need of fertilization very depended on the chemical fertilizers such as Urea,
Super Phosphate, and Muriate of Potash (MOP) as main source fertilizers of N, P, and K. Related to
reduce the dependenly on the use of chemical fertilizers, recently, it has been introduced some biofertilizers
that have some benefits to crop growth through their capability in increasing nutrients
absorption from soil even also could suppress soil borne pathogens.
Bio-fertilizers are living microorganisms applied to soils in the form of inoculants to facilitate
or provide a particular mineral nutrient required by crops through a mutual symbiotic or nonsymbiotic
relationship (Simanungkalit, ). Several living microorganism or microba such as
arbuscular mychorrizas (AM) fungi, non symbiotic nitrogen-fixation bacteria, phosphate solubilizing
bacteria, and hormon producing bacteria have been reported that the microba have possitive effect in
increasing growth and yield of crops (Bolan, 1991; Bagyaraj, 1990; Gaur and Rana, 1990; Widada et
al., 2002). In addition, soil bacteria and mychorrizas was also reported that the microba could increase
crop nutrient uptake, especially N, P, K, S, Zn, Cu, and Fe (Kabirun and Widada, 1995).
The current research results show that bio-fertilizers can increase the efficiency of fertilizer
use. The use of bio-fertilizer alone can give the highest efficiency but the low yield levels. To obtain
higher yield levels the application of integrated fertilizer management principles is the best by
combining the application bio-fertilizer and chemical fertilizer in a way that the amount of applied
chemical fertilizer does not suppress the growth and development of microorganisms in the biofertilizer
(Simanungkalit, ).
String bean is one of vegetable crops that lots cultivated by farmers in Merapi mount slope
areas in Sleman Regency, Yogyakarta Special Region at which most soil developed from volcanic
sediment. Meanwhile, fertilitation recomendation that commonly used by farmer was 23 kg N+54 kg
P 2 O 5 +60 kg K 2 O/ha.
This paper elaborate the results of a research about the effect of bio-fertilizer and N, P, K chemical
fertilizer applications to string bean (Phaseolus vulgaris L.) yield and population of soil borne
pathogen (Fusarium spp and Ralstonia spp) on a soil formed from volcanic sediment at Merapi
volcano slope area in Sleman, Yogyakarta Special Region.
MATERIALS AND METHODS
The research was carried out on a soil formed from volcanic sediment in Merapi volcano
slope area with altitude of 450 m above sea level at Pakem, Sleman Regency, Yogyakarta Special
Region. Physico-chemical characteristics of surface layer soil (0-20 cm) used for the experiment site
was presented in Table 1. In general, the soil has sandy loam texture, very low organic content, low
cation exchange capacity, slighty acid but very high in base saturation. The content of potential and
available P and K was very high and moderate, respectively while the N content was low (Balai
Penelitian Tanah. 2005). The soil could be interprated that it has moderate fertility with moderate
capability in water holding, macro nutrient supply and retain, except N.
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Prosiding SeminarNasional Pekan Inovasi Teknologi Hortikultura Nasional: Penerapan Inovasi Teknologi Hortikultura
dalam Mendukung Pembangunan Hortikultura yang Berdaya Saing dan Berbasis Sumberdaya Genetik Lokal,
Lembang, 5 Juli 2012