Influence of lime and farm yard manure

4.1.5. Total exchangeable acidity

The total exchangeable acidity varies from 1.88 to 1.92 and 1.80 to 1.92, respectively before and after experiment. The figure below shows the variation of total exchangeable acidity according to treatments:

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Figure : Total exchangeable acidity before and after experiment

The figure above shows that the total exchangeable acidity has increased for T₀, and decreased for other treatments. It has slightly decreased for treatments that have received organic amendments and a wide variation (decrease) is observed on treatments that have received mineral amendment (lime).The ANOVA table shows whether the observed difference is significant.

Table : ANOVA table for soil exchangeable acidity

Source of variation	DF	SS	MS	F Observed	F.Table at 1% threshold.
Total	27	1.456	0.0539	-	-
Block	3	0.0251	0.0083	0.75	5.09
Treatment.	6	1.233	0.2055	18.66	4.01
Error	18	0.1982	0.0110	-	-

CV %= 2.63

The above ANOVA table shows that there is high significant difference between treatments at threshold of 1 %as the F table is greater than Calculated F at 1 % threshold. The difference observed between blocks is not significant as the F ratio is lower than the value of F .table at the same threshold

Table : Mean separation for total exchangeable acidity after experiment

Treatments	Means in meq/100 of soil	Homogeneous group
T0 T1 T2 T3 T4 T5 T6	1.91 1.89 1.86 1.86 1.85 1.82 1.80	A AB B B B C C

From the mean separation of total exchangeable acidity, it sin observed that the treatments are classified into five homogeneous groups (A, AB, B, C, D).

The increase in total exchangeable acidity for T₀ is due to slight decrease in organic matter and basic cations due to leaching by rainfall.

The decrease of total exchangeable acidity is due to the property of organic matter compounds that neutralize the active acidic cations and the acidity neutralizing power of lime (Nyle, 2003).

4.1.6. Exchangeable Calcium and Magnesium

The quantity of Ca and Mg present in soil before experiment varies respectively from 0.62 to 0.64 meq/100gr of soil and 0.26 to 0.28meq/100gr of spoil. According to Pietrowich (1985), the soil Ca content classifies the soil in «excessively poor «range while the Mg content classifies the soil in «very poor « range. The figure below shows the Ca variation according to treatments before and after experiment:

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Figure : Variation in Ca content according to treatments before and after experiment

From the figure 8, there has been Ca depletion for T₀, no variation in Ca content for T₂ and T₃, slight increase in Ca content for T₄, T₅ and T₆, which are treatments that have received the mineral amendments (lime). The ANOVA table below shows whether the difference observed between treatments is significant

Table : ANOVA for exchangeable Ca content after experiment

Source of variation	DF	SS	MS	F Observed	F table at 1 % threshold
Total	27	4.323	0.160	-	-
Block.	3	0.0778	0.0259	0.79	5.09
Treatment.	6	3.653	0.608	18.51	4.01
Error	18	0.591	0.0328	-	-

From the ANOVA above, it is observed that there is a significant difference between treatments at 1 % threshold as the value of F observed is greater than the value of F table at the same threshold. The difference observed between blocks is not significant as the F ratio is lower than the value of F .table at the same threshold.

Table : Mean separation for exchangeable Ca content after experiment

Treatments	Means meq/100g of soil	Homogeneous group
T6 T5 T4 T3 T2 T1 T0	0.75 0.71 0.67 0.64 0.63 0.625 0.6	A A B B BC C C

From the above mean separation, it is observed that the treatments are classified into four groups (A, B, BC, and C).

The low level of Ca in T₀ is attributed to Ca uptake by crops, and leaching due to rainwater percolation. For T₁,T₂ and T₃, there has been no increase and slight increase in Ca content, which is due to, according to GAUCHER, coted by NKUSI(1984), chelating power of organic ions compounds to Ca^2+,Al³⁺, and Fe³⁺, though it supplies a certain quantity of Ca during decomposition and mineralization.

The remarkable increase in Ca content for T4, T5 and T6 is due to high supply in Ca from applied lime to respective treatments. The figure below shows the variation of Mg before and after experiment according to treatment

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Figure : Variation of Mg content according to treatments

From the figure above, it seems that the Mg content has been decrease for T0, slightly decreased in T1, constant for T2, T3 ad T4, slightly increased for T5 and T6. The ANOVA table below shows whether the difference observed between treatments is significant.

Table : ANOVA for exchangeable Mg after experiment

Source of variation	DF	SS	MS	F Observed	F Table at 5 %threshold
Total	27	802.29	29.72
Block.	3	74.00	24.67	0.88	5.09
Treatment.	6	197.62	32.93	1.15	4.01
Error	18	530.67	27.98

From the above table, there is no significant difference between treatments as the value of observed F is lower than the value of F table at 5 % threshold.

The difference observed between blocks is not significant as the F ratio is lower than the value of F .table at the same threshold

The decrease in T0 is due to Crop uptake and loss due to leaching by rainfall water.

The no variation for T2, T3 and T4 is due to supply of small quantity of Mg by the amendments applied and reduction leaching due to improved water holding capacity by organic amendment.