as integral components of soil quality. Microbial biomass C (C mic ), basal respiration (R mic ), and enzyme activities have been widely used in soil investigations as a result of their great sensitivity to anthropogenic disturbance and environmental
glucosinolate hydrolysis products than other high-value vegetable crops in which Brassicaceae meals are likely to be used ( Stiehl and Bible, 1989 ). Evaluation parameters included carrot emergence, yield, quality, and N content as well as microbial biomass N
The inclusion of cover crops into cropping systems may influence soil microbial activity which is crucial to sustained crop production. A study was conducted to measure short term effects of summer and winter cover crops on soil microbial biomass carbon (MBC) in a cucumber-tomato rotation system. The experiment was established in Summer 2002 as a factorial of summer cover crops (planted either as fallow or after harvest of cucumbers) and winter cover crops (planted in September). The design was a split-block with four replications. The main plot factor was summer cover crop and consisted of five treatments; sorghum sudangrass fallow (SGF), cowpea fallow (CPF), sorghum sudangrass after cucumber (SGC), cowpea after cucumber (CPC) and bareground fallow (BGF). The sub-plot factor was winter cover crop and consisted of three treatments including cereal rye (CR), hairy vetch (HV) and bareground (BG). In spring of 2003, soil samples were collected in each treatment at 30 days before (30 DBI), 2 days after (2 DAI) and 30 days after (30 DAI) cover crop incorporation. MBC was measured using the chloroform fumigation-incubation method. Both summer and winter cover crops affected soil microbial activity. MBC in the summer cover crop treatments at 30 DBI was 47.7, 51.4, 49.2, 43.7 and 42.5 μg·g-1 soil for SGF, CPF, SGC, CPC and BGF, respectively. At 30 DAI, 113.1, 88.9, 138.5, 105.6, and 109.3 μg·g-1 soil was obtained in SGF, CPF, SGC, CPC, and BGF plots, respectively. Soil MBC was similar at 2 DAI in the summer cover crop treatments. Among winter treatments MBC was similar at 30 DBI and 30 DAI, but significant at 2 DAI with values of 62.8, 53.3, 59.3 μg·g-1 soil for CR, BG, and HV, respectively.
Bokashi) was reported to increase rice ( Oryza sativa L.) grain yield; this was associated with increased soil organic matter content, microbial biomass, and available nutrients as well as improved soil porosity and permeability compared with organic and
microbial biomass N (MBN) in mg·kg −1 . Soil subsamples were fumigated with ethanol-free chloroform for 5 d, extracted with 0.5 M K 2 SO 4 , and total extractable N was reduced to NH 4 + with persulfate and Devarda’s alloy for NH 4 + absorbance readings at
). Soil mineral N [including nitrate (NO 3 − )–N and ammonia (NH 4 + )–N], soil soluble organic N, soil microbial biomass N, and soil fixed ammonium are important labile soil N fractions that are actively involved in N mineralization and immobilization
are important characteristics for most floriculture crops. In our experiment with petunia, product 1 improved both flower numbers and biomass, whereas product 2 only increased total flower biomass ( Fig. 5D and E ). Treatment with various microbial
2 weeks of collection for fresh soil analyses. Remaining soil was dried at 35 °C for 72 h and ground to 2 mm for dry soil analysis. Extractable nitrogen (ExN), potentially mineralizable nitrogen (PMN), and microbial biomass (MB) analyses were
(cv. Yusuan No. 1) to assess the effects of relay intercropping on cucumber plant growth, soil enzyme activities and microbial diversity, and biomass and community diversity. Materials and Methods Experimental materials and treatments. The experiments
% over 5-min periods following the principles of Bouwer (1986) . Soil microbial biomass carbon (MBC) was determined by fumigation-extraction ( Anderson and Ingram, 1993 ). Briefly, 5 g of soil was extracted with 0.5 m potassium sulfate in 1:4 ratio (v