Milo I. Harpstead

Bio: Milo I. Harpstead is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 52 citations.

The Classification of Some Nigerian Soils

Abstract: This study presents data on soil profile samples from eleven sites in Nigeria, widely distributed from the high rainfall coastal area of sedimentary parent material to the dry northern area where aeolian deposits from the Sahara Desert have been a major soil-forming factor. Weatherable minerals are generally present in the soils formed from crystalline rocks and most of these soils are classified as Alfisols. On the sedimentary rocks and on the ultrabasic crystalline rocks Oxisols have formed. On aeolian parent materials from the Sahara and on the Pleistocene sediments the soils are classified as Inceptosols.

EFFECT OF ORGANIC AND INORGANIC FERTILIZER ON YIELD AND CHLOROPHYLL CONTENT OF MAIZE (Zea mays (L.) AND SORGHUM Sorghum bicolour (L) Moench)

Abstract: The effects of amending soil with organic (poultry manure) and inorganic fertilizer on yield and chlorophyll content of maize (Zea mays L.) and sorghum (Sorghum bicolour (L) Moench) was carried out at the Teaching and Research (TR was highest under control plots in both crops. The implication of CSI% on drought tolerance of maize and sorghum was discussed.

Effect of organic and inorganic fertilizer on yield and chlorophyll content of maize ( Zea mays L.) and sorghum Sorghum bicolour (L.) Moench)

Abstract: The effects of amending soil with organic (poultry manure) and inorganic fertilizer on yield and chlorophyll content of maize (Zea mays L.) and sorghum (Sorghum bicolour (L.) Moench) was carried out at the Teaching and Research (T&R) Farm of the Obafemi Awolowo University, (O.A.U.) Ile - Ife, Nigeria. The experiment was a randomised complete block design (RCBD), laid out in a split-plot arrangement in the second cropping season of year 2001 and 2002. There were four sources of fertilizer for soil amendment: inorganic fertilizer (IF), mixture of inorganic fertilizer and poultry manure (IFPM), poultry manure (PM) and control (C) (no fertilizer or manure treatment). Each fertilizer source supplied 54 kg N plus 25 kg P2O5 and 25 kg K2O5/ha. There were significant variability and diversity observed on the two crops due to treatments. Grain yield was highest in sorghum (3.55 kg/ha) and maize (2.89 kg/ha) under IFPM followed by IF treatment for maize (2.33 kg/ha) and PM treatment for sorghum ((3.37 kg/ha). Sorghum and maize had the highest dry matter of 72.3 g/plant and 71.0 g/plant under IFPM at harvest. The effects of PM on the dry matter of sorghum (68.1 g/plant) and maize (61.7 g/plant) were not significantly different (p = 0.05) from that of IF (sorghum 66.1 g/plant, maize 58.7 g/plant). Sorghum also had the highest leaf area (LA) (2752.9 cm2/plant) and total chlorophyll content of 3.28 mg/g under PM while maize on the other hand had the highest LA (1969.5 cm2/plant) and total chlorophyll content of 2.63 mg/g under IFPM. In both maize and sorghum, the lowest chlorophyll content occurred in control plot. Drought tolerance measured as percentage chlorophyll stability index (CSI%) was highest under control plots in both crops.

Aggregation and organic matter fractions of three Nigerian soils as affected by soil disturbance and incorporation of plant material

Abstract: Soil management involving organic matter incorporation and reduced tillage intensity has often been reported to improve soil structure. However, the mechanisms and roles of soil organic matter (SOM) fractions in the process of soil structural stabilisation are not well documented. Furthermore, documentation of their positive effects on soils in the tropics is scarce. This study examined the changes in soil structure in response to SOM fractions dynamics in an incubation experiment. Three Nigerian soils: Iwo series (Oxic Tropudalf), Itagunmodi series (Tropeptic Euthrothox) and Owode series (Oxisol) were incubated with ground barley straw ( Hordeum vulgare L.) or green ryegrass ( Lolium perenne L.) with and without disturbance of the soil during incubation. The incorporation of plant material significantly increased the light fraction organic matter (LFOM) with density −3 but had no effects on the heavy fraction polysaccharides (HFPS), i.e. polysaccharides attached to heavy fraction soil minerals with density >1.7 g cm −3 . A significant decline of LFOM was recorded with time of incubation (0–41 days: 21%, 30% and 36% decrease for the no plant material treatment, the barley straw treatment, and the green ryegrass treatment, respectively). This was associated with a significant rise of HFPS. Furthermore, the added plant material clearly decreased the soils' fraction of dispersible clay even before incubation, which was interpreted as a direct effect of the LFOM on the clay. Therefore, the use of dispersible clay as an indicator of macro-aggregate stability is questioned. After 41 days of incubation the concentration of water-stable aggregates was on an average 9% higher for soils with added plant material relative to soils not receiving plant material. When packing the post-incubation soil in metal cores, the volume of pores with equivalent neck diameter >10 μm was from 0.024 to 0.033 m 3 m −3 higher and the saturated hydraulic conductivity 18–24% higher for soils with added plant material than for soils without. Disturbance of the soil during incubation reduced the concentration of water-stable aggregates by 7% relative to undisturbed. Also the volume of pores with a neck diameter >10 μm and the saturated hydraulic conductivity were significantly reduced (by 6% and 19% relative, respectively) when the soil was disturbed during incubation. The results demonstrate that rapid changes of SOM fractions can occur over a short incubation period and that these changes have a pronounced positive effect on the structure of these tropical soils. It also suggests that incorporated plant material may correct tillage induced degradation of soil physical properties over a relatively short time.