The Effect of Organic Fertilization in Soil Microorganisms and the Productivity of Two Crops of Brassica Family( Cabbage – Cauliflower)

Nesrin  nakadli
General Commission of Scientific Agricultural Research-
GCSAR/ HOMS  Research Center
Faculty of Agriculture- ALbaath University,
2010

Abstract

An experiment was carried out to study the effect of organic fertilization and nitrogen fertilizer on cabbage and cauliFlower crops for two seasons, the  included  6 treatments (control , cow manure ,  sheep manure , chicken manure , compost , and nitrogen fertilizers ). Organic fertilizers were added as similar rate of N in urea (50 kg/N/ha) according to the content of soil nitrogen and Ministry of Agric. and Agra. Reform.S.(Recommendation).
This study has been done on some biological properties of soil  (the number of some physiological groups of soil microorganisms , soil respiration ,in addition to nitrate concentration in plant and (Cabbage -Cauliflower) productivity were determined.
This investigation shows for Cabbage crop that the number of ,Bacterial assimilation mineral form of nitrogen, Actinomycetes , Azotobacter, Phosphate solubilizing microorganisms, Mesophilic cellulose decomposting microorganisms and Spor-forming bacteria ( Bacillus) increased in most treatments amended with organic fertilizers comprising to control , whereas the number of, Actinomycetes , Azotobacter , Phosphate solubilizing microorganisms Fungi , Mesophilic cellulose decomposting microorganisms and Clostridium pasteurianum  decreased in treatment amended with nitrogen fertilizers as compared to control.
No significant differences noticed in the intensity of soil respiration test  between treatments at two seasons for cabbage crop.
The concentration of nitrate increased on the heads of Cabbage in treatments amended with nitrogen fertilizers and treatment amended with cow manure at the first season ,whereas the increasing of nitrate on the head of Cabbage at second season was in treatment amended with  chicken manure.
The yield of cabbage increased in treatments amended with chicken manure at the first season, whereas the productivity of Cabbage increased in  treatments amended with cow manure at the second season.
The results show on CauliFlower crop  that the number of Bacterial assimilation mineral form of nitrogen , Actinomycetes , Azotobacter, Phosphate solubilizing microorganisms , Mesophilic cellulose decomposting microorganisms and Spor-forming bacteria ( Bacillus) in most treatments that amended with organic fertilizers was increasing in compared to  control , and the number of Ammonification bacteria , Actinomycetes , Azotobacter , Phosphate solubilizing microorganisms, Fungi , Mesophilic cellulose decomposting microorganisms and Clostridium pasteurianum  in the treatment that amended with nitrogen fertilizers was decreasing ,this treatment was the lowest in compared to all treatments even the control.
No significant differences noticed in the  intensity of soil respiration test  between treatments at first seasons for CauliFlower crop. , whereas the intensity of soil respiration increased in treatments amended with nitrogen fertilizer at the second season.
The concentration of nitrate increased on the floral curd of CauliFlower in treatments amended with nitrogen fertilizers and treatment amended with cow manure at the first season ,whereas the increasing of nitrate on the floral curd of CauliFlower at second season was in treatment amended with  cow manure.
The yield of CauliFlower increased in treatments amended with chicken manure at the first season, whereas the productivity of CauliFlower increased in treatments amended with cow manure at second season.
Key words: soil , Organic Fertilization ,Nitrogen fertilizer, Microorganisms , Soil respiration ,nitrate , Productivity .