^ ^ ^ / ^ LAND AT BRirrONS HALL FARM, CHIGNALL ST. JAMES NR. CHELMSFORD, ESSEX SOILS AND AGRICULTURAL LAND CLASSIFICATION 1. FEBRUARY 1987 RURAL PLANNING SERVICES, V BROADWAY HOUSE, "' 130C BROADWAY, J DIDCQT, OXON 0X11 8UB
1. INIRODUC11 ON 1.1. This report desn.ies ttie soils and Agriultural Land Classifiation (ALC) of about 70ha (173 ares) of land at Srittons Hall Farm, Chignall St. James, near Chelmsford, Essex, 1.. It IS based on a study of published information and on tne results of a site inspetion arried out on January and February 1987. 1.3. The publisned information onsulted inluded: (a) Geologial Survey Sheet A0 (Eppmg) at 1:50,000; (b) Soil Survey of England andrialessheet 161 (Saffron Walden) a reonnaissane map at 1:63,630 and aompanying report; () Soil Survey of England and Wales, National Soil Map Sheet i\ (Eastern England) at 1:0,000 and aompanying Regional Bulletin; (d) ALC Sheets l^h (Saffron Walden) and 161 (London N.E.) at 1:63,3 aompanying Regional Bulletin; (e) Meteorologial Offie map of mean annual rainfall (194170) 1:6,000. 1.^. Setion of tnis report desrides tne physial harateristis of the site as they affet land quality, based on tne published information and observations made during the site inspetion. 1.5. The main purpose of the site inspetion was to provide fuller information about the soils from whih a detailed ALC of the site ould be produed.
1.6. Ill borings were made by 1.m duth hand auger at the loations shown on RPS 1. Desriptions of the borings are given in Appendix 1 and the types of soils found are disussed in Setion 3. A soil map is attahed as RPS. 1.7. Setion 4 disusses the detailed Agriultural Land Classifiation of the site, with detailed ALC maps presented as RPS 3/1 and 3/. U E
. PHYSICAL CHARACTERISTICS OF THE SITE Loation and Land Use.1. The site onsists of a blok of land, of apout 63h3 (156 ares) lying south of the hamlet of Chignall St James, and a smaller blok of about 7ha (17 ares) between Chignall St James and Chignal Hall to the North East... All the land is m arable use exept for tnree small fields east of Pengymill whih are used for horse grazing and a strip of the permanent grass on the valley floor of the River Can at the northwest orner of the site..3. The southwest orner of the smaller northern blok is not in agriultural use having had assorted materials tipped and/or stored on it and witn bushes and small waste heaps dotted over it. Topography.4. The land is part of the entral Essex Boulder Clay Plateau, falling away to the valley of the River Cam whih forms the western boundary of both bloks..5. The height varies from about 37m to 44m (115 to 1ft), and there is a general absene of steep slopes. Muh of the eastern half of the site is basially flat while the western half has gentle slopes down to the River Cam. L.6. Thus there are no agriultural limitations imposed either by altitude or gradient. Climate 7. The site has the typial, somewhat ontinental limate of south Essex, with relatively high summer and low winter temperatures..8. The main annual ramtall is about Jmm (3.6 inhes), a relatively low figure for southeast England.
Geology.9. The geologial map shows virtually the entire land as part of the extensive spread of Chalky Boulder lay in Central Essex..10. A narrow strip of alluvium is shown along the floor of the Can valley but only the extreme southwest orner of the smaller northern blok extends onto this. The map also shows a narrow strip of glaial gravels and a superfiial drift alled Head at the southwest orner of the main blok, overlooking Pengymill. Soils.11. The northern blok is overed by the Soil Survey map sheet 141 whih shows Chalky Boulder Clay soils (Hanslope and related series) on the highest ground nearest the road, soils on glaial gravels (Chelmer and related series) in a broad band aross the entre of the blok, and poorly drained layey soils (Fladbury series) on the alluvium in the extreme southwest orner. This is, however, only a reonnaissane map, and so the soil types and soil boundaries should not be taken too literally..1. Both bloks are now overed by Sheet 4 of the 1:0,000 National Soil Map but this gives only a very simplified piture of the soils. Both bloks are shown mostly as Assoation 511j (Stretham) with Assoiation 571x (Ludford) along the Can Valley..13. This is simply another way of making the basi distintion between layey soils on the Chalky Boulder Clay and gravelly soils along the valley sides, the ommon soil pattern in Central and South Essex. I.14. It may be noted, however, that in this viinity the Chalky Boulder Clay soils have been assigned to the Stretham Assoiation found on partiularly halky lay and whih are regarded as better drained than the more ommon Hanslope Assoiation on the Chalky i3ouider Clay.
.15. Investigations elsewhere where this Stretham Assoation has been shown, however, have failed to demonstrate that the soils were any more halky or better drained than normal. ALC.16. The site is on the overlap between Sheets l^b and 161, whih follow the onvention in the area of lassifying virtually all tne Boulder Clay as Grade, the Gravels, Head and Alluvium on the valley sides and floors as Grade 3..17. Thus most of the site is shown as Grade with Grade 3 where the ground falls away towards the River Can..18. More detailed investigations have, however, shown that tne Boulder Clay an give gradings ranging generally from Grade to depending on drainage. The gravel head and lay soils also give a range of land qualities whih an only be determined following detailed site inspetions. n
3. SHE INSPECTION SOILS 3.1. The site inspetion revealed that virtually all the undisturbed soils on the arable land had Chalky Boulder Clay. Only 11 of the 105 borings onerned failed to reah Chalky Boulder Clay, and most of these are thought to have Chalky Boulder Clay below auger depth. 3.. The horse grazing paddoks in the extreme southwest did have gravelly soils, however, but muh disturbed by former small gravel digging operations. On the arable land only two borings (no 53 and 111) both in low lying positions had stony layers at depth indiating the presene of gravels nearby. Otherwise these soils resembled the others on the site. i, 3.3. Thus the distintion on the reonnaissane maps, and by impliation on the ALC map, that the higher ground was Chalky Boulder Clay, the lower ground was over gravels, is! not orret. Instead, the whole site should be regarded as having soils on Chalky Boulder Clay (or their dealified j equivalents). 3.4. The harateristi soil of the Chalky Boulder Clay is a ( 1 alareous lay or lay loam over alareous lay, passing down into yellowish brown Chalky Boulder Clay (Soil Type A). i These soils, whih would be lassed as the Hanslope series by the Soil Survey of England and Wales were found at 78 of { the 11 boring loations. 3.5. Similar soils ie. lay loams over lay, but nonalareous, ij at least in the surfae were also found (Soil type B). These ii would be lassed as the Faulkbourne series (or one or two r with redder subsoils as the Bengeo series), 19 examples of " suh soils were found, about half overlying Chalky Boulder r7 Clay within auger depth. Ei 3.6. Site investigations of similar terrain elsewhere m South and Central Essex have shown that suh non alareous layey soils an be quite ommon and substantial areas of them an
be piked out on a soil map. At Chignal Hall, however, they appear to our as isolated small pathes sattered throughout the broad zone of alareous Hanslope soils. The only disrete areas of suh nonalareous soils onsidered wo rth separating out on the soil map, RPS, are near the no rtheast orner of the mam blok and in one of the most easterly fields adjaent to the River Can. 3.7. All these alareous (Soil Type A, Hanslope) and nonalareous (Soil Type B, Faulkbourne/Bengeo soils) show signs of drainage impedane aused by the slow permeability of the underlying lay. This feature has an important bearing on the ALC gradings and will be disussed further in setion 4, There is, however, little evidene for the belief of the Soil Survey (see para.14 above) that this site is part of an area where the soils are either more halky or better drained than soils elsewhere on the Chalky Boulder Clay. 3.8. One path of partiularly badly drained soils was found near J the southwest orner of the main site. These soils (Soil Type C) were also of heavier textures with nonalareous lay topsoiis and were overall heavier and stiffer than the other layey soils on the site. These soils would probably be lassed as the Ragdale or Dak Series (borings 51 36 inlusive). Similar soils were also found as isolated borings at loations 9 and 99. 3.9 The horse grazing paddoks m the extreme southwest had an assortment of soils all showing signs of disturbane and the whole area has a broken, hummoky topography with small I ''; pits, obviously having formerly been dug for gravel (or mari). This assortment of soils is shown as soil type 0 on the soil map. i 3.10. One auger boring (no 10) was in the alareous loamy alluvium of the River Can and would probably be lassed as the Rib series. For onveniene it too, is inluded as one of the 'assorted soils' on the map and in the appendix. i
3.11. Thus the soil pattern of the Brittons Farm site an be summarised as: Almost all the soils are developed in Chalky Boulder Clay with the ommonest being alareous lays or lay loams over lays (Soil Type A, Hanslope series). There are two pathes and oasional isolated borings of similar but non alareous soils (Soil Type 3, Faulkbourne/Bengeo series), but these are relatively rare. Heavier, stiffer soils (Soil type C, Ragdale/Uak series) are also rare but our in a small path near the southwest orner and as oasional isolated borings elsewhere. The only examples of soils overlying gravels (Soil Type D) are in the horse grazing paddoks in the extreme southwest earner, but these have been disturbed by former gravel or marl digging operations. One boring is loated on the alluvium of the River Can. k t
9. 4. AGRICULTURAL LAND CLASSIFICATION 4.1. The main limitations of most of the soils on the site are their heavy textures and impeded drainage, aused mainly by the impermeable lay subsoils. The heavy textures prelude any of the soils from Grade 1, and so gradings in the Grade Grade 3 range are indiated. 4., By onvention, ALC Grades have been applied in Eastern England for soils over boulder lay aording to the depth from the surfae at whih olour mottling indiative of impeded drainage is first enountered. The riteria also take aount of whether the mean annual rainfall is above or below inhes. Sine at Brittons Hall Farm it is about 0m (3.6 inhes) the relevant riteria beome: Grade Not mottled within 40m of the surfae Subgrade Mottled within 40m but not within 30m of the surfae Subgrade Mottled within 30m of the surfae 4.3. In all ases, it is assumed that the soil textures are aeptaole for these gradings, and m the majority of the Brittons Hall Farm soils this is the ase, with the topsoil textures being lay loams or alareous lays. However, if the topsoil is a nonalareous lay as in Soil Type C then tne ALC riteria require a grading no higher than Subgrade 3. 4.4. The disturbed gravelly soils in the horse grazing paddoks are graded 4 beause of the poor soils, the broken topography and the disturbed harater of the area, though perhaps even Grade 5 might be a more realisti grading.
V.i ^.5. When the gradings for eah of the auger borings are plotted on a map (RPS 3/1) a very ompliated pathwork of gradings appears. 4.6. With the exeption of the disrete areas of 3 and 4 assoiated with Soil Types C and D respetively, the majority of the site exhibits almost a random distribution of grades varying from to on Soil Types A and 8. 4.7. The map indiated some boundaries between these grades, but they are regarded as somewhat speulative. Given the same individual auger boring loations it would be possible to draw alternative boundaries, and it is thought probable that alternative borings near those whih are reorded ould give different gradings and so a ompletely different ALC map. 4.8. Furthermore, it should be noted that the 'depth to mottling' riterion is somewhat arbitary and overs a narrow depth band within the soil profile so perhaps it is not surprising that suh a omplex pattern of gradings results, 4.9. Also it IS debatable if the farmer would really notie the soalled differenes in land quality, although there might be yield variations Certainly, however, the omplex pattern is suh that the areas of better Grade ould not be separately exploited, nor the poorer areas avoided. 3"5 4.10. Of the 87 individual roughly equally spaed borings on Soil Types A and 3, 3 are Grade, 38 and Subgrade and 31 are Subgrade 3. It therefore seems that it would be reasonable the 'average out' these gradings Assuming then that the 8 Grade 'balane out' the 31 of Subgrade an overall grading of for most of the site would be indiated 4.11. Thus, the final ALC map for the site beomes RPS 3/ showing virtually the whole site as Subgrade (but with individual borings in the to range), with small areas of Subgrade 3 and Grade 4 at the southwest orner, eah ouoying about 5?o of the site.
11 APPENDIX 1 AUGER BORING DETAILS Soil Type A Calareous lays and lay loams over lay developed in Chalky Boulder Clay (Hanslope series). (a) Typial Profile (No 44) 0 4m Dark brown alareous lay 4 36m Brown alareous lay 36 51m 3rown alareous lay with ohreous mottles 51+m Pale brown halky lay with ohreous and grey mottles (ChalKy Boulder Clay) (b) summary of horizon depths et. of similar profiles Notes 'e' estimated depth (irregularity ploughed surfae) lay l lay loam i, ( No Calareous Depth Topsoil Texture Cal areous Cla / Loam Sub soil Clay Chalky Boulder Clay Oepth to mottles (m) ALC / t j > > "1 J :n ) i J u 3 4 5 6 7 3 10 11 15 16 17 18 0 73 4 6 7 8 9 30 31 3 33 34 0 ^ 0 6 0 6 0 4 0 4 0 0 3 0 0 4 0 0 4 0 0 0 4 0 3 0 4 G 3 0 0 6 0 0 3 0 4 0 3 0 6 0 4 0 l l l l l l i 4 6 4 4 _ 3 39 3 49 _ 3 3 4 4 3 6 3 4 8 6 ^ 4 45 34 8 4 4 44 40 43 44 55 38 43 50 40 43 44 3+ 39+ 6+ 4+ 4+ 45+ 34+ + 8+ 4+ 49+ 44+ 4+ 3+ 40+ 43+ 44+ 55+ + 33+ 43+ 50+ 40+ 43+ 64+ 4 46 6 4 4 54 34 33 34 31 6 33 34 46 3 33 55 43 31 53 4 3 33 h'4 5a 30 5a 5a ia
1 No Topsoii (Dark brown lay loam) Calareous Subsoil Texture Clay loam Clay Chalky Depth Boulder to Clay mottles (m) ALC 1. li I 36 37 38 39 40 41 4 43 44 46 47 49 57 58 59 61 6 63 64 65 66 67 63 69 70 71 7 73 74 75 76 77 73 79 80 81 83 89 90 91 95 96 100 105 104 105 106 107 109 IIJ 09 07 06 0 04 0 06 06 04 04 06 03 0 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 0 e 03 0 07 07 0 04 06 03 08 04 03 07 04 08 06 0 09 0 0 U 'J 03 0 l l l l l l l i l 3 53 4 36 5d 9 95 7 85 95 6 40 4 9 4 51 6 65 + 30 50 50 50 45 40 45 40 8 30 43 7 38 7 33 53 4 6 33 3 46 8 43 4 44 7 4 3 6 53 4 54 41 9 55 54 53+ 56 43 3 51 5J 7 95+ 85+ 6+ 95+ 4+ + 6+ 40+ 9+ 51+ 65+ + 30 50 50 50 45 40 45 40 80 43 38 33 53 + 38+ 46+ 43+ 44+ 3+ 53+ 4+ 54+ 41+ 3+ 55+ 54+ 45+ 51 + 7 + 30 7 3 4 38 6 4 36 43 53 75 45 55 45 45 48 33 5 48 4 6 36 8 75 37 34 4 38 43 36 37 3 44 36 3 55 5b
15 Soil Type B Non alareous lay loams over lay, usually with Chalky Boulder Clay at depth (Faulkbourne or Bengeo series) (a) Typial profile (No 13) Q 3m Dark brown lay loam 3 37m Brown lay loam 57 loum Brown iay with ohreous mottles 100+m Pale brown halky lay with ohreous and grey mottles (Chalky Boulder Clay). (b) Summary of horizon depths et. of similar profiles. No Topsoii Subsoil Chalky Depth ALC (Dark brown Nonalareous Boulder to lay loam) Clay ohreous Clay loam Clay mottles (m) h 1. I 1 0 + 43 9 0 3? 3795 95+ 37 1 0 3 + 8 5b 13 0 3 3 57 37 100 100+ 37 14 0 4 4 3 3 75 75+ 3 19 0 6 6 4 4 53 53+ 3 1 0 43 43+ 0 6 6+ 45 0 70 70+ 48 0 80 30+ _ 37 50 Q 8 3+ 44 87 0 7 7 50 50+ _ SO 93 0 8 3 5 5+ _ 3 94 0 _ 53 53+ 97 0 7 _ 7 95 95+ 56 93 0 4 4+ _ 3 101 0 3 _ 3 57 57+ 3 ^103 0 3 3 95 95+ _ 95 111 07 745 4565 45 Note : Stoniness prevented augering beyond 65m in boring 111
u Soil Type C Poorly Drained lays (Ragdale or Oak series) (a) Typial profile (No 56) 0 (e}m Dark greyish brown nonalareous lay 45m Greyish brown nonalareous lay with ohreous mottles 45 50m Greyish brown nonalareous lay with ohreous and grey mottles 50+m Greyish brown nonalareous halky lay (Chalky Boulder Clay). (b) Summary of horizon depths et. of similar profiles. Notes 'e' estimated depth (irregularly ploughed surfae) No Topsoil (Non alareous iay) Subsoil (Clay) Chalky Boulder Clay Depth to mottles.(m) ALC 51 5 53 54 55 56 9 99 0 e 0 e 0 e 0 e 0 e 0 e 06 06 3 50 30 30 ^ 50 6+ 6 67 3 + 33 + 30 30 50 67 + 6 6 3 3 3 3 3 3 3 3 Note : Stoniness prevented augering beyond 55m in boring 55 1. Li M
15 Soil Type D Assorted Soils 8 0 OB l B with ohreous mottles, stony + Too stony to auger 83 0 40 B l, stony (Not Topsoii) 40+ Too stony to auger 34 00 DB humous l with ohreous mottles al 0 38 G & 3 mottled l al. 38 50 LG i Y6 mottled l al, 50+ Too stony to auger 85 As 84 86 015 D3 humouse sl 15+ DB gravel Disturbed profile 10 015 slightly humouse, al 15 37 GB 37+ GB with ohreous i grey mottles 3?
16 BRITTONS HALL FARM, CHIGNALL ST JAMES SOILS AND ALC Summary Almost all the soils are developed in Chalky Boulder Clay with the ommonest being alareous lays or lay loams over lays (Soil Type A, Hanslope series) as shown on RPS. There are two pathes and oasional isolated borings of similar but nonalareous soils (Soil Type 3, Faulkbourne/Bengeo series), but these are relatively rare. Heavier stiffer soils (Soil Type C, Ragdale/Qak series) are also rare but our in a small path near the southwest orner and as oasional isolated borings elsewhere. The only examples of soils overlying gravels (Soil Type D) are in the horsegrazing paddoks in the extreme southwest orner, but these have been disturbed by former gravel or marl digging operations. One boring is loated on the alluvium of the River Can, The main agriultural limitations of the soils are their heavy textures and onsequent impeded drainage. Using the riterion of depth to mottling onventionally applied to suh soils in Eastern England, a omplex pattern appears of almost equal proportions of Grades, and 5b. (see RPS 5/1). It is suggested that, realistially the average or overall grading for this land (about 90io of the site) is Subgrade (See RPS 3/). Near the southwest orner the heavy, poorly drained lays (Soil Type C) and the disturbed gravelly soils (Soil Type D) give land of Subgrade 3 and Grade 4 respetively, eah about 3% of the site. ''