Agriculture Reference
In-Depth Information
The following two sustainability indices are
by Pal and Sahu ( 2007 ):
1
b 0 i
where b 0 i
is the regression coefficient in y ij ¼ a þ b 0 i y 0 j and
Sustainability index SI ð 4 Þ¼
where y 0 j
is the average yield for
j th year excluding the yield for
i th treatment in the particular year ;
1
c 0 i
c 0 i
y ij ¼ a þ b 0 i t þ c 0 i y 0 j and
Sustainability index SI
ð
5
Þ¼
where
is the regression coefficient in
y 0 j
where
is the average yield for
j
th year excluding the yield for
i
th treatment in the particular year
:
These two measures also do not have limits
for sustainability. Another serious objection to
all these four measures is the assumption of
linearity of the regression. If the linearity of the
regression is not valid, then the above measures
will be put under question.
Sahu et al. ( 2005 ) proposed the sustainability
index based on the average performance and the
highest ever performance during the period of
investigation with the help of the following
formula:
In this measure, sustainability has been
visualized as the minimum deviation of the aver-
age performance over the highest ever achieved
performance during the period of investigation.
As such, the lower the value of the index, the
higher the sustainability.
In addition to the above, Pal and Sahu ( 2007 )
proposed the following indices to measure
sustainability which do not require any assump-
tion of linearity:
Þ¼ Y max Y
Y
Sustainability index SI
ð
6
:
s i
y i s max ;
Sustainability index SI
ð
7
Þ¼
where
s i
is the standard deviation of
i
th treatment over the entire period,
y i
th treatment over the entire period,
s max is the maximum value of the standard deviation of all the treatments
is the average of
i
;
X
y ij y max
1
n
Sustainability index SI ð 8 Þ¼
y i
j
where
y i
th treatment over the entire time period,
y max is the maximum value of the
is the average of
i
i
th treatment over the time period
;
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