The effect of supplemental irrigation from polyacrylamide-treated microcatchments on the growth of acacia saligna in dryland

Figures & data

Figure 1. The rainfall distribution over the years 2011 to 2012.

Table 1. The physical and chemical soil properties for the experimental area.

clay	silt	sand	pH	EC	Field capacity	Welting point	Bulk density	CaCo3	Na
%	%	%		dS/m	%	%	(gm/cm^3)	(gm/kg)	(gm/kg)
34	44	22	8.02	0.79	30	21	1.11	193	130

Table 2. Runoff volume (L) generated by PAM-treated, plastic mulch and natural plots.

Storm	Rainfall	PAM A-130	PAM A-836	PAM Aerotil	Plastic mulch	Natural plot
Date (d/m/y)	(mm)	(L)	(L)	(L)	(L)	(L)
02/01/2009	6.5	0.0	0.0	0.0	130.3	0.0
05/01/2009	1.3	0.0	0.0	0.0	24.5	0.0
22/02/2009	0.9	0.0	0.0	0.0	0.0	0.0
28/03/2009	1.9	2.8	1.3	1.4	37.2	2.5
16/04/2009	5.3	0.0	0.0	0.0	106.5	0.0
25/11/2009	7.1	9.0	8.0	1.3	46.0	5.0
08/12/2009	9.2	23.7	19.5	2.2	48.3	24.2
09/12/2009	0.7	0.0	0.0	0.0	3.5	0.0
13/12/2009	0.3	0.0	0.0	0.0	2.2	0.0
30/12/2009	3.0	0.0	0.0	0.0	19.3	0.0
Total for 2009	36.2	35.5	28.8	4.9	417.8	31.7
14/01//2010	14.0	118.3	125.2	90.7	131.0	124.7
19/01/2010	32.4	66.8	65.3	27.3	129.7	80.0
25/01/2010	22.0	103.7	109.0	82.0	131.0	91.3
30/01/2010	46.5	42.9	22.5	23.9	46.2	22.5
04/02/2010	10.0	0.0	0.0	0.0	4.7	0.0
01/03/2010	47.0	60.4	31.0	13.6	131.0	49.7
Total for 2010	171.9	392.1	353.0	237.5	573.6	368.2
1/18/2011	7.4	32.5	17.3	8.3	94.3	38.0
31/01/2011	11.5	10.3	13.3	13.8	55.0	15.8
06/02/2011	5.2	8.2	5.3	9.0	104.2	9.1
14/02/2011	1.9	0.3	0.3	0.2	37.2	0.2
27/03/2011	44.7	5.7	6.1	5.5	73.9	6.4
07/04/2011	7.4	3.5	2.2	1.8	93.0	3.9
03/05/2011	22.3	14.0	6.7	16.2	130.0	20.8
17/05/2011	9.7	9.3	3.7	9.7	74.0	15.5
Total for 2011	110.1	83.9	55.0	64.5	661.6	109.6
3 years total	318.2	511.5^b*	436.8^c	306.9^d	1653.0^a	509.5^b

*Values with the same letters are not significantly different at probability level (p = 0.01) based on the LSD test.

Figure 2. Schematic diagram representing the field experimental layout of PAM treatments and land covers as well as the Acacia saligna trees.

Figure 3. Runoff coefficients for PAM-treated plots compared to natural plots (no PAM no plastic mulch).

Figure 4. The number of acacia leaves under different treatments.

Figure 5. The plant height (cm) under different treatments.

Figure 6. The stem diameter (cm) under different treatments.