The factors affecting chemical use in aquaculture in the Central Coast Region of Vietnam

Figures & data

Figure 1. Researchers’ model of the factors affecting the use of inorganic chemicals in coastal aquaculture in the SCR.

Table 1. The dependent variable and the independent variables included in the model, along with their symbols and measurement units.

Number	Symbol	Variable definition	Unit	Expectations marked*
	SDHC	Dependent variable: chemical use	kg/rod/farming season
I	HV	Education level	Encoded from 0 to 16 with 0: preschool and 16: postgraduate	−
II	G	Price of inorganic chemicals		−
	G1	Price of minerals, vitamins	Likert scale with 1: very low and 5: very high
	G2	Price of antibiotics	Likert scale with 1: very low and 5: very high
	G3	Price of probiotics	Likert scale with 1: very low and 5: very high
III	NT	Awareness of the production process		−
	NT1	Attending local training courses	Likert scale with 1: absolutely not, and 5: lot
	NT2	Awareness of productivity	Likert scale with 1: absolutely not, and 5: lot
	NT3	Awareness of land resource protection	Likert scale with 1: absolutely not, and 5: lot
	NT4	Awareness of water resource protection	Likert scale with 1: absolutely not, and 5: lot
	NT5	Awareness of disease prevention	Likert scale with 1: absolutely not, and 5: lot
	NT6	Awareness of natural disaster prevention	Likert scale with 1: absolutely not, and 5: lot
IV	TD	Awareness of the harm caused by inorganic chemicals		−
	TD1	Impacts on water and soil	Likert scale with 1: absolutely not, and 5: lot
	TD2	Impacts on productivity	Likert scale with 1: absolutely not, and 5: lot
	TD3	Impacts on health	Likert scale with 1: absolutely not, and 5: lot
V	KNHL	Fishery extension training policies		+/−
	KN1	Training on improving productivity	Likert scale with 1: absolutely not, and 5: lot
	KN2	Training on disease prevention	Likert scale with 1: absolutely not, and 5: lot
	KN3	Training on pond rehabilitation	Likert scale with 1: absolutely not, and 5: lot
	KN4	Training on irrigation	Likert scale with 1: absolutely not, and 5: lot
	KN5	Training on seed selection	Likert scale with 1: absolutely not, and 5: lot
	KN6	Training on protection of land and water	Likert scale with 1: absolutely not, and 5: lot
	KN7	Training on natural disaster prevention	Likert scale with 1: absolutely not, and 5: lot
VI	KNHT	Fishery extension support policies		+/−
	KN8	Production capital support	Likert scale with 1: absolutely not, and 5: lot
	KN9	Machinery and equipment support	Likert scale with 1: absolutely not, and 5: lot
	KN10	Expert support	Likert scale with 1: absolutely not, and 5: lot
	KN11	Seed support	Likert scale with 1: absolutely not, and 5: lot
	KN12	Support for natural disaster damage	Likert scale with 1: absolutely not, and 5: lot
VII	THT	Participation in cooperatives	Likert scale with 1: absolutely not, and 5: lot	+/−

* +: Expected to increase; −: Expected to drop.

Table 2. Results from the regression of factors affecting the use of chemicals in the aquaculture model

Model summary^b
Model	Multiple correlation coefficient R	R^2	Revised R^2	Standard error of the estimate	Durbin–Watson
1	0.652^a	0.524	0.502	1.36924	1.881
Coefficient^b
Model	Unstandardised coefficients B		Standardised coefficients	Value (t)	Level of significance (Sig.)	Multicollinearity inspection
	B	Standard error	Beta			Acceptability	VIF
(Constant)	2.800***	1.027		2.727	0.007
LnG	−0.271	0.505	−0.039	−0.536	0.593	0.845	1.183
LnNT	0.113	0.426	0.018	0.264	0.792	0.939	1.065
LnKNHL	−0.498***	0.175	−0.201	−2.837	0.005	0.888	1.126
LnKNHT	−0.747***	0.287	−0.196	−2.605	0.010	0.789	1.267
LnTHT	0.706**	0.322	0.151	2.194	0.029	0.946	1.057

^a The independent variables: (Constant), LnTHT, LnKNHL, LnG, LnNT, LnKNHT.

^b The dependent variable: LnSDHC.

^** Level of statistical significance at 5%.

^**** Level of statistical significance at 1%.

Table 3. Analysis of variance (ANOVA) of the factor model: impacts on inorganic chemical use in aquaculture

ANOVA^b
Source	Total squared	Degrees of freedom	Square means	F	Sig.
Between groups (ESS)	52.068	5	10.414	5.554	0.000^a
Individual group (RSS)	367.464	196	1.875
Sum (TSS)	419.532	201

^a The independent variables: (Constant), LnTHT, LnHV, LnKNHL, LnG, LnNT, LnKNHT.

^b The dependent variable: LnSDHC.