Effects Of Continuous Cultivation Research Articles

Effect of continuous cultivation and soil texture on some soil properties

The effects of soil continuous cultivation and soil texture on some of its properties, electrical conductivity, total porosity, and calcium carbonate content and soil penetration resistance. Six samples of soil material for a layer of 0-30 cm were collected from three different texture sites are Clay, Loam and Loamy Sand in Basra Governorate for three sites Abi al-Khasib, Karma and Zubair. Three of these samples represented the treatment of soil continuous cultivation, soil planted with alfalfa crop (Medicago sativa) for 7 consecutive years, and the other three samples from the same sites for uncultivated soil with three replications for each sample. The results showed a decrease in the values of electrical conductivity, calcium carbonate, soil penetration resistance, and an increase in soil porosity values in cultivated soils. The lowest EC values were 4.1, 5.3 and 6.2 dS. m-1 for soils with textures Loamy sand, Loam and Clay, respectively, and for CaCO3 of 182.3 g. kg-1 in Loamy sand, 266.7 g. kg-1 and 310 g. kg-1 for Loam and Clay soils, respectively, and for resistance to penetration of 550 KN.m-1 for clay soils. While it was 620 KN.m-1, and 714 KN.m-1, for loam soil and loamy sand soil, respectively, compared to uncultivated soil. While the soil porosity values increased for cultivated soils compared with uncultivated soils and the values of 43%, 48.53% and 53.4%, for soils with textures Loamy sand, Loam and Clay respectively, And for the average weighted diameter of 0.2537 mm, 0.2817 mm, 0.3640 mm, for soils with textures Loamy sand, Loam and Clay, respectively.

Effect of continuous cultivation and soil texture on some soil properties

Effect of continuous cultivation and soil texture on some soil properties

Effect of land use on infiltration characteristics of soils in Northern Akwa Ibom State, South-eastern Nigeria

Knowledge of infiltration characteristics of soils is necessary for designing quality soil management and conservation practices on agricultural and urban lands. This is predicated upon accurate evaluation of the infiltration characteristics of the soil. A study was conducted to evaluate the effect of three land use practices, namely, oil palm plantation (OP), bush fallow (FL) and continuous cultivation (CC) on the infiltration characteristics of soils formed on sandstone parent material in northern Akwa Ibom State, south-eastern Nigeria. Infiltration was measured with the double ring infiltrometer for a cumulative time of two (2) hours and the data generated fitted into the Philip two term infiltration equation. Results showed that differences in final infiltration rate (if) and cumulative infiltration (I) were significant (p≤0.05) between OP and FL. Also, there were significant (p≤0.05) differences between OP and CC in initial infiltration rate (io), final infiltration rate (if), cumulative infiltration (I), and sorptivity (S). However, the trend was OP>FL>CC. Differences between FL and CC were not significant. Generally, low infiltration characteristics were recorded in CC than in FL and OP and indicated the degradative effect of continuous cultivation on soil properties and crop production especially where crop residues are not incorporated into the soil. Results from OP and FL suggest that occasional fallowing may be necessary to alleviate infiltrationimpeding soil surface conditions and improve soil and water conservation for crop production in the study area in Akwa Ibom State. Keywords : Land use practices, infiltration characteristics, soil water storage, soil properties, sandstone parent material

Use efficiency of tropical rainforest soils of southwestern Nigeria as affected by agronomic practices

Tropical soils generally have extremely delicate nature and lack resilience to recover once degraded. This is aggravated with increase in demographic pressure on land which has led to continuous and intensive cultivation of the land. With soil quality information, management options can be developed so as to improve the capacity of the soil to function within various ecosystem boundaries. This paper comprises of results of five experiments and it is a review of efforts made by the soil quality team of the Institute of Agricultural Research and Training, Nigeria, to identify physical, chemical and biological soil attributes that can serve as useful indicators in assessing the effects of management on soil quality. Five experiments were conducted by the team to assess effects of continuous cultivation, tillage practices, cropping systems and land use (tree versus arable crops) on soil quality. Our findings show that soil quality is aggraded, degraded or sustained, depending on the type of use and management options. Conventional management methods degraded soil quality indicators while farmers’ traditional practices minimize soil quality degradation. It is recommended that farmers’ practices that will protect sensitive soil quality indicators are panacea to soil quality management in forest ecology of the tropics.Keywords: Soil quality, management options, forest ecology, indicators, degradation

Effects of continuous cultivation on Ferrosols in subtropical southeast Queensland. I. Site characterization, crop yields and soil chemical status

The productivity of Ferrosols used for rainfed agricultural production in the south and central Burnett regions of south-east Queensland was examined in relation to the duration under continuous cultivation. A range of crops grown in on-farm situations during 1986-90 were examined using paired sites to assess the extent of yield decline with time under cropping. The changes in soil chemical characteristics that have occurred during the cropping period were also assessed. All locations showed evidence of a significant reduction in crop growth (50-100%) where continuously cropped sites were compared with sites which had either never been cropped or which had been under grazed grass pasture for >20 years. In the absence of severe late season water deficits, this reduced growth rate was always reflected in lower (21-72%) crop yields at maturity. However, crop dry matter (DM) could interact with crop water use under conditions of late-season water deficit to negate, or even reverse, early growth advantages on previously untilled soil. At least part of the observed yield reduction on continuously cropped soil was due to nutrient deficiencies resulting from depletion of both surface and subsurface reserves during cropping. Long-term cropping has resulted in depletion of soil K and Zn (especially in the subsoil), organic carbon and total N status, and caused significant acidification of both surface and subsoil layers despite the use of lime. The decline in subsoil K status and falling subsoil pH have severe implications for crop performance in dry seasons, when crops rely on subsoil reserves to sustain crop growth. The decline in soil N status has occurred despite a high frequency (>50%) of grain legumes in the crop rotations practised on all farms monitored, and illustrates the small N return from these crops under rainfed conditions. The reduction in soil organic carbon due to cropping was extreme, with continuously cropped areas having organic carbon levels of only 0.9 to 1.5% in the 0-10 cm layer-values which were only 25-40% of levels in untilled soil. Grazed grass leys were only partly successful in restoration of soil organic carbon status.

Effect of Continuous Cultivation with Animal Manuring on a Sub-Sahelian Soil near Maiduguri, North Eastern Nigeria

Effect of Continuous Cultivation with Animal Manuring on a Sub-Sahelian Soil near Maiduguri, North Eastern Nigeria

Microbial dynamics in a continuously stirred tank reactor with 100% cell recycle

ABSTRACT: Effects of continuous cultivation on the dynamics of heterogenous populations were investigated by employing a continuously stirred tank reactor (CSTR) with 100% cell recycle to minimize biomass waste and any shifts in microbial populations. Phenol was used as model substrate and as the sole carbon source. Activated sludge bacteria, acclimated to phenol, were grown in a CSTR with 100% cell recycle operated at the same dilution rate but with different influent phenol concentrations. During the steady state, the kinetic parameters for the Haldane model (µm, Ks, and K1) characterizing growth on phenol were determined by a long‐term batch experiment. The dominant microbial species at each steady state were analyzed by biochemical assays. There was a shift in microbial species at different influent phenol concentrations with a corresponding change in µm values whereas the values of Ks and K1 were not influenced. Even though the changes in microbial populations and kinetic parameters were attributed to changes in the influent phenol concentration, there was no direct correlation between them.

Agricultural land use and soil degradation in a part of kwara state, Nigeria

Because of the alarming rate of increase in population all over tropical Africa, and the consequent need to grow more food, several writers have suggested the practice of continuous or permanent cultivation in place of the traditional bush fallowing system. This suggestion has been made without recognising the natural vulnerability of tropical soils and the associated problems of actual soil degradation, especially in situations where fertilizer inputs are limited. This study examines the effects of different land use practices on actual soil degradation in a part of Kwara State, Nigeria. This involves comparing the physical and chemical properties of the soils in areas under continuous cultivation, fallow and forests, and using the technique of factor analysis to isolate indices which best describe these phenomena. The results show that the main effects of continuous cultivation in the area examined were to increase the acidity of the soil, that soil organic matter content was likely to double after 10 years of fallow conditions, and that continuous cultivation was capable of reducing the cation-exchange capacity of soils by at least one-third.

EFFECTS OF DIFFERENT CROPPING SYSTEMS AND OF A SOIL CONDITIONER (VAMA) ON SOME SOIL PHYSICAL PROPERTIES AND ON GROWTH OF TOMATOES

Soil physical condition resulting from different cropping systems was examined on a number of New Brunswick soils and compared with that of the adjoining soils which had been under continuous grass.Continuous cropping to potatoes reduced the percentage of water-stable aggregates and porosity. Other effects of continuous cultivation were a reduction in soil organic matter content, available water capacity and cation exchange capacity.VAMA (soil conditioner) increased the percentage of water-stable aggregates and the porosity of the cultivated soils. On the continuous-grass soils these properties were not affected. Other effects of VAMA were an increase in cation exchange capacity and a reduction in available water capacity on all soils.Yields of tomatoes in the greenhouse were lower on the soils which had been cropped continuously to potatoes than on the corresponding soils which had been under continuous grass. VAMA increased yields of tomatoes on the continuous-potato soils. The increase in yield due to VAMA was directly related to increase in percentage of water-stable aggregates and total pore space.