Properties of soil in Chiba university's environmental horticulture and forestry (Tone koreichi) farm, 2: A few inorganic elements and the composition of clay minerals

We investigated the composition of clay minerals and a few inorganic elements of the soils in the apple garden (TNF-3: A, Bw, 2A and 2Bw) and Japanese ceder (Cryptomeria japonica) forest (TNO -5: Ap, 4Bw, 5AB and 6A) in Chiba University's Environmental Horticulture and Forestry (Tone Koreichi) Farm. And we also clarified the following items. 1. Past surface soils and subsoils were buried under the present surface soils (A and Ap horizon) and subsoils (BW horizon) in both TNF-3 and TNO-5. The arrangement of soil horizons were A, Bw, 2Aand 2BW horizons in TNF-3 and Ap, 2BC, 3BC, 4Bw, 5AB and 6A horizons in TNO-5. 2. Contents of Available phosphorus (Av-P) of present surface horizons (A, Ap) were higher than those of subsoils and buried horizons in both TNF-3 and TNO-5. Especially, that of Ap horizon in TNO-5 was 8 times as high as A horizon in TNF-3. On the contrary, phosphate adsorption coefficients (PAO of A and Ap horizons were lower than those of subsoils in both TNF-3 and TNO-5 and there was the high and positive correlation between PAC and estimated contents of allophone. 3. Though cation exchange capacity (CEO of A horizon was higher than those in Bw, 2A and 2 Bw horizons in TNF-3, those of 5AB and 6A horizons were higher than Ap horizon in TNO-5. Exchangeable calcium, magnesium, potassium and base saturation ratios (BS) of each horizon in TNO-5 were higher than those in TNF-3. 4. Proportion of coarse sand of A (or Ap) horizon was higher and those of clay, silt and fine sand of A (or Ap) horizon horizons were lower than those in the subsoils in both TNF-3 and TN0-5. 5. The proportion of oxides, amorphous clay minerals and crystalline clay minerals of clay fraction of A and Ap horizon were about 30, 40 and 30% respectively in both TNF-3 and TNCh5. Those of 2A horizon in TNF-3, 4Bw, 5AB and 6A horizons in TNO-5 were about 10, 30 and 60%. There were less oxides and amorphous clay minerals and more crystalline clay minefals in 2A horizon in TNF-3 and in 4Bw. 5AB and 6A horizons of TNOH5. 6. Aluminium-vermiculite and chlorite were dominant and aluminium-smectite, smectite and vermiculite were subdominant in each horizon of TNO-5 and TNF-3.