Influence of lime and farm yard manure

CHAPTER 4. Results and Discussion

4.1. Soil chemical properties

4.1.1 The soil reaction

The p H before experiment varies from 5.6 to 5.9 and 4.5 to 4.7; respectively for p H water and pH KCl (1N) .These data show that, according to norms of interpretation established by RUTUNGA (1980) found on appendix1, the soil is classified into «very acidic» to «moderately acidic» soils. The pH water and KCl (1N) after experiment varies respectively from 5.7 to 6.5 and 4.6 to 5.6.

The mean values of p H water are shown on the figure below:

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Figure : pH water before and after experiment according to treatments

From the figure 2, it is remarked that the pH has remained constant for T0 (which has not received the amendments) and increased for other treatments that have received different doses of amendments. The ANOVA table below shows whether the difference observed between treatments is significant.

Table : ANOVA for the pH water after experiment

Source of variation	DF	SS	MS	F.Observed	F.table at1% threshold
Total	27	5.924	0.219
Block.	3	0.0869	0.0289	0.31	5.09
Treatment.	6	4.198	0.699	7.68	4.01
Error	18	1.6391	0.091

CV % = 6.4

The ANOVA above shows that the difference between treatments is significant at 1 % threshold as the value of observed F is greater than the value of F table 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 pH water after experiment

Treatments	Mean	Homogeneous group
T6 T5 T4 T2 T3 T1 T0	6.5 6.32 6.2 6.1 6 6.01 5.7	A A AB B B B C

The mean separation above shows that the treatments are classified into four homogeneous groups (A, AB, B, and C).

The treatments that received organic amendments (T₁, T₂, T₃) show the slight increase in pH; and that is due, according to NKUSI(1984) and KHASAWNEH (1986), deactivation of acidic cations (Al, Fe ,H) by organic compounds produced during humus formation. The high increase in pH has been observed in treatments that have received mineral amendments. This phenomenon is a result of higher capacity of lime to lower soil acidity.

The figure below shows the variation of pH KCl according to treatments.

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Figure : p H KCl before and after experiment

The figure above shows the almost no variation for T₀ (Control) and the increase in

pH KCl for treatments that have received the amendments. The ANOVA table below shows whether the difference observed between treatments is significant.

Table : ANOVA for pH KCl after experiment

Source of variation	DF	SS	Ms	F.Observed	F.Table at 1% threshold
Total	27	5.99	0.22
Block.	3	0.0794	0.026	0.79	5.09
Treatment.	6	4.111	0.685	20.75	4.01
Error	18	0.598	0.033

CV %= 4.8

The ANOVA table above shows that there is a significant difference between treatments as the value of observed F is greater than the value of F table at 1 % threshold. The mean separation below classifies treatments in homogeneous groups according to their performance. 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 pH water after experiment

Treatments	Mean	Homogeneous group
T6 T5 T4 T2 T3 T1 T0	5.6 5.51 5.3 5 4.9 4.9 4.6	A A AB B B B C

The mean separation above shows that the treatments are classified into four groups (A, AB, B, and C).

As stated for pH water, the increase in pH KCl (1N) for the treatments received amendments is due to neutralization of active acidic cations by organic compound and the power of lime to reduce the active soil acidity (NKUSI, 1984).