SW25

Grazing paddock (dairy)		Site Code	SW25	Ferric (& Sodic), Eutrophic, Brown CHROMOSOL
		Location	Camperdown
		Landform	Undulating basalt hills
		Geology	Quaternary–Newer volcanics (scoria)
		Element	Valley floor


Horizon	Depth (cm)	Description
A11	0-10	Very dark brown (10YR2/2); very fine sandy clay loam; weak coarse blocky, parting to moderate medium polyhedral structure; very firm consistence (dry); pH 5.3; gradual boundary to:
A12	10-30	Very dark greyish brown (10YR3/2); very fine sandy clay loam; moderate medium polyhedral, parting to moderate to strong fine polyhedral structure; pH 5.3; firm consistence (moist); clear boundary to:
A2	30-50	Dark brown (10YR4/3); conspicuously bleached; gravelly clay loam; contains many (50%) medium size (2-10 mm) ferruginous nodules; pH 6.2; abrupt boundary to:
B21	50-60	Dark brown (7.5YR4/4); medium clay; moderate coarse polyhedral, parting to strong medium polyhedral structure; strong consistence (dry); pH 6.7:
B22	60-80	Dark brown (10YR4/3); medium heavy clay; strong coarse prismatic, parting to medium prismatic parting to moderate coarse blocky structure; strong consistence dry; pH 7.0:
B23	80+	Dark brown (7.5YR4/2) with yellowish brown (10YR5/8) mottles; medium clay; strong coarse prismatic, parting to medium prismatic parting to moderate coarse to medium blocky structure; pH 7.2.


Management considerations
Strong texture contrast between the surface soil and the subsoil is a very important soil feature. This can have a major effect by reducing and/or redirecting the internal drainage and restricting root growth beyond the upper horizons. Options include reduced tillage, improving organic matter content and altering the subsoil through artificial drainage (ripping, mole drainage) and/or chemical amelioration (gypsum) to improve structure. Ferruginous and Ferromanganiferous nodules, concretions and pans can restrict root penetration and limit available water holding capacity where there are sufficient amounts, often forming a discontinuous or continuous pan where concentrated (>50%). They are also an indication of a periodic waterlogging. Either shallow rooted species can be planted to avoid the nodules, subsoil drainage may need to be considered, possibly in conjunction with deeper rooted plants which could puncture the nodule layer and access available water and nutrients stored below.

Analytical data

Site SW25	Sample depth	pH		EC	NaCl	Ex Ca	Ex Mg	Ex K	Ex Na	Ex Al	Ex acidity	FC (-10kPa)	PWP (-150kPa)	KS	FS	Z	C
Horizon	cm	H₂O	CaCl₂	dS/m	%	cmol_c/kg	cmol_c/kg	cmol_c/kg	cmol_c/kg	mg/kg	cmol_c/kg	%	%	%	%	%	%
A11	0-10	5.3	4.7	0.31	0.02	7.9	1.6	1.2	0.1	N/R	N/R	38.6	16	9	34	21	22
A12	10-30	5.3	4.6	0.11	N/R	6.7	2	0.4	0.1	N/R	N/R	34	12.2	9	37	23	23
A2	30-50	6.2	5.3	0.07	N/R	5.1	2.6	0.3	0.2	N/R	N/R	27.9	11.2	23	34	17	22
B21	50-60	6.7	5.8	0.11	N/R	6.2	8.4	0.2	0.8	N/R	N/R	43.8	28.1	6	16	8	64
B22	60-80	7	6.1	0.14	N/R	5.9	11	0.3	2	N/R	N/R	51	32	3	12	11	71
B23	80+	7.2	6.2	0.16	N/R	6.6	15	0.3	3.2	N/R	N/R	53	30.6	5	20	16	56

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