difficult on relatively infertile and depleted soils, where improved nutrient cycling by such catch crops is most highly demanded. Our experiments confirm that even under relatively infertile growth conditions, Chicory seems to be an unusually efficient catch crop for deep soil nitrate-N, much better than Ryegrass and the N-fixing catch crops. Even then, there were no significant effects of any of the catch crops on yield, or N, P or K uptake of the barley, so this difference in catch crop nitrate depletion did not carry over to the succeeding crop.
Previous studies (, , , and ) have established the presence of some heavy metals in excess of the permissible limits set by FEPA and WHO in some of the effluents that are being discharged into the streams and the waters of the stream. If this is the case the use of industrial liquid waste for irrigation poses great danger to the soil and the crops. An assessment carried out by  showed high levels of manganese, lead and iron in water application as well as in the irrigated soil. A similar study by  attempted an assessment of the effect on ground water pollution. The study showed tolerable levels of mercury (0.05mg/l) and lead (less than 1 mg/l) in River Salanta (a tributary of River Tatsawarki) upstream of the site where effluent is discharged into the river. At the point of effluent discharge, the levels increased above the permissible limits of 17.5mg/l of mercury and 20.5mg/l of lead. The water used for irrigation had the highest concentration of lead (28.5 mg/l) and mercury (405mg/l). However, samples of shallow well water showed low levels of mercury and lead suggesting limited or no groundwater pollution . Also,  identified concentration of heavy metal (iron, lead, manganese and chromium) in excess of the permissible limits set by FEPA. In this paper, an assessment of the level of heavy metals in soils used for irrigation of vegetable crops along the Tatsawarki River in Kano is presented, and the suitability of the soil for irrigation determined.
depend on chemical species (Teng et al., 2011). The aim of this study is to evaluate vanadium levels in calcareous soils and food chain crops along northwestern coastal region of Egypt. As a rare element, there are few studies in literature focused on vanadium pollution and content in plant. These areas contain new industrials cities that may increase the emission of vanadium in soils and consequently plants. Vanadium fractions and mobility index were investigated in soil and plant samples.
Many plants that are candidates for refining into biofuels also possess qualities that make them potentially useful for managing soilborne pests, reclaiming polluted soils, supple- menting animal feed and other pur- poses. Phytoremediation with these plants may provide a practical and economical method for managing the movement of trace elements into water tables, surface- and tail-water runoff, and drainage effluent. Mus- tards (Brassicaceae) are of particular interest for biodiesel, and grasses (Gramineae) for bioethanol produc- tion. These plants, as well as others such as certain members of the onion family (Alliaceae), also possess prop- erties that could make them effective natural biofumigants for soil. Some of these crops have high allelopathic activity and must be employed care- fully in rotations to avoid damaging subsequent crops.
A mix of mineral and organic fertilizers might seem to be a good compromise between two fertilization-principles. This impression is re-enforced, if one studies the yield-values concerning potatoes, summer wheat, the first harvest in the clover/grass ley or the yield of beet-tops and wheat-straw. Compared to this, did K4 show surprisingly low values at many investigations in the soil. In the topsoil the values of P and Mg-content was low, while the C and N contents was above the mean value. Urease-activity was very high in the topsoil to decrease at a faster pace in the deeper soil-layer than average in the trial. The dehydrogenase-activity was relatively low in all soil-layers. The mixed fertilized variant had a certain implication to make zones between topsoil and sub-soil. Above all in the deepest soil-layer, but also just right under the plough-depth, the values was distinctly lower than average. The crop given the mixed fertilizer gave relatively low quality. This was showed above all, in the time-related investigations and maybe most distinct concerning receptivity towards fungi-infestation. Above all, it was the chopped-fruits that gave worse quality. Summer wheat that was only fertilized with mineral fertilizer, did not deviated in quality from the other variants. In the clover/grass ley, the mixed fertilized variant had together with K8 the lowest amount leguminous plants at the first, as well as the second harvest. The leguminous plants had in this variant hard to hibernate, while the grass and above all, the timothy showed a very good hibernation. Total-image of this type of fertilization is in other words very complex. It appears to a great deal, to be the opposite of the unfertilised variant. It has difficulties to force its way down to depths, but also to maintain itself in the time-based analyses and during the later part of the trial period. According to the light- shadow-scheme K4 can be referred to as being more on the shaded side. The crops showed a lot of immature characters.
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www.ijaer.in Page 138 Fertility management range from recurring fertilizer applications to low external input based on organic sources of nutrients. Although both extremes work well in specific circumstances, they pose major limitations for most smallholder farmers in Africa. Fertilizer use is the obvious way to overcome soil-fertility depletion, and indeed it has been responsible for a large part of the sustained increases in per capital food production that have occurred in Asia, Latin America, and the temperate region, as well as in the commercial farm sector in Africa (Borlaug and Dowswell, 1994). There is nothing wrong, biophysically or environmentally, with fertilizers when properly used. Fertilizers provide the same nutrients as organic sources to plants. Plants cannot distinguish nitration-phosphate ions they absorb from organic inputs from those they absorb from mineral fertilizers (hereafter referred to as inorganic fertilizers). Most smallholder farmers in Africa appreciate the value of fertilizers, but they are seldom able to apply them at the recommended rates and at the appropriate time because of high cost, lack of credit, delivery delays, and low and variable returns (Heisey and Mwangi, 1996). Such constraints are largely due to the lack of an enabling policy environment in rural areas caused by the deficient road and market infrastructure typical in most African countries. The price of fertilizers in rural areas of Africa is usually at least twice the international price (Bumb and Baanante, 1996). Transport costs are about seven times higher in Africa than in the united state of America (USA) Structural Adjustment Programmes in the last decade has tripled or quadrupled fertilizer prices in relation to crop prices in many African countries (Bumb and Baanante, 1996). Furthermore, since fertilizer recommendations are normally formulated to cover broad areas with diverse soils, farmers also lack information about the best fertilizer to use for their particular fields and cropping practices, making the crop response to fertilizers more erratic and less profitable.
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The traditional methods of solid waste management by disposal in ‘waste landfills’; wastewater treatment by ‘sewage treatment plants’; land remediation by ‘earth cutting and soil excavation’; and agriculture production by ‘aggressive tillage and land plough’ & use of agrochemicals are all highly expensive & also pollute the environment, emit greenhouse gases inducing global warming. Vermicomposting by earthworms can divert 60-70 % solid wastes from landfills. Vermifiltration involves ‘low energy’ and no ‘sludge’ is formed which requires safe disposal in landfills. Vermiremediation is ‘on-site’ without earth cutting and soil excavation. With continued use of vermicompost farm soils becomes too soft requiring very low tillage. Earthworms works as natural ploughman. We have successfully experimented in ‘vermicomposting of solid wastes’, ‘vermifiltration of ‘municipal and industrial wastewater’, ‘vermiremediation of chemically contaminated soils’ and ‘vermi-agroproduction of cereal and vegetables crops’ with amazing results. Wastes are degraded by over 75% faster & the end-product is highly nutritive organic fertilizer; BOD and TDSS of wastewater is reduced by over 95% & the water become ‘disinfected & detoxified’ to be used in agriculture; chemicals from the contaminated soils are significantly removed also making it fertile; growths of crop plants are enhanced by 30–40% higher over chemical fertilizers by vermicompost.
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In commercial production of pineapple, nematicides have been widely used to manage Meloidogyne spp. However, nematicides pose serious threat to the ecosystem (Sharma and Pandey, 2009), leading to most countries banning their use due to these adverse effects (Li et al., 2011; Singh et al., 2012). Environmental and human health concerns regarding nematicide use against Meloidogyne spp. has led to an increased interest to explore alternative strategies which are environmental friendly. Biological control has shown promise as an economically and ecologically friendly approach to reduce pest damages (Davies et al., 1991; Hussain et al., 2011; Singh et al., 2012). Several organisms are known to be antagonistic to plant parasitic nematodes. It has been demonstrated in several soils that nematophagous fungi increase under some perennial crops and under those grown in monocultures, and so may control some nematode pests, including Meloidogyne (Stirling, 2011). Although biological control is a potential component of nematode management program in pineapple, currently, this component is lacking in commercial pineapple plantations. This study therefore explores the occurrence of plant parasitic nematodes in commercial pineapple farms in Kenya and the effect of Trichoderma spp. and Purpureocillium lilacinum on the Meloidogyne spp. present. This is important since there are no previous reports on use of BCAs on management of Meloidogyne spp. in Delmonte and Kakuzi commercial pineapple plantations.
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Field crops constituted the predominant land use type, ac- counting for approximately 82 % in 1985 and 71 % in 2016. Plantation forest also increased from 3.9 % in 1985 to 9 % of the watershed in 2016. In 1980, to remedy the degrad- ing effects of monoculture of annual cropping, deforestation, and overgrazing on pastures and forests, a programme devel- oped by ODESYPANO (Office Development Sylvo-Pastoral Nord Ouest) and financed by the World Bank implemented some conservation activities, including development of per- manent vegetative cover using olive trees and sylvo-pastoral management. An agroforestry (agro-sylvo-pastoral) system was introduced in 1982 as an alternative programme for de- velopment and conservation in the region. This system in- cluded converting annual cropping into a combination of an- nual crops inter-planted with olive trees (in this study classi- fied as “permanent crops”). This area increased from 3.4 % in 1985, when it was introduced for the first time in the region, to 7.3 % in 2016. The local farmers took this alternative as they believed that their soils had become poor and no longer gainful for annual crop production. Grazing land remained almost unchanged in terms of area, as it is spread over bad- lands, barren lands, and riverbanks with a high concentration of eroded and poor soils.
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Agricultural resources are important renewable dynamics natural resources. In India, the agricultural sector alone sustains the livelihood of around of 70% of the population and contributes nearly 35% of the net national product. Increasing agricultural productivity has been the main concern, since the scope for increasing area under agriculture is rather limited. This demands judicious and optimal management of both land and water resources. Hence comprehensive and reliable information on land use and cover, forest area soils, geological information, extent of wastelands, agricultural crops, water resources (both surface and underground) and hazards of natural calamities like drought and floods are required. Remote sensing systems, having capability of providing regular, synoptic multi temporal and multi spectral coverage of the country, play an important role in providing such information. A large number of experiments have been carried out in developing techniques for extracting agricultural related information from ground borne, air borne and space borne data. Some of the broad agricultural application areas are:
When conditions of vertisol soils were hard and dry in the dry season, root growth will also be hampered and nutrient uptake from the soil will also be restricted. Under these conditions, it is very likely that soybean plants require a good symbiosis with arbuscular mycorrhizal fungi (AMF), because their tiny external hyphae can explore much larger volume of soil and help their host plants to take up more nutrients and water compared with the roots (Smith and Read, 2008). However, the establishment of arbuscular mycorrhizal (AM) symbiosis naturally by soybean grown after paddy rice is possibly hampered by the generally very low population of AMF after paddy rice crops, which are normally irrigated with flooded irrigation system, as has been reported by several researchers (Ilag et al., 1987; Wangiyana et al., 2006).
SHS have unique cropping systems with practices such as agroforestry, crop rotation, and intercropping being dom- inant (Figure 1). To meet their subsistence needs, these farmers opt to grow a diverse number of crops in their small-sized farms. These practices have numerous benefits; for example, there are studies that have been done to evaluate the advantages attributed to intercropping . Intercrop- ping is beneficial to plants in the context of preventing soil erosion, improving soil texture, promoting better water penetration, resource use efficiency, and supplying organic matter in addition to promoting the colonization of symbiotic microbes such as indigenous AMF in soil (Figure 1). A recent meta-analysis of 290 published glasshouse and field trials to investigate the effects of various agricultural practices on mycorrhizal colonization led to the finding that inoculation increased mycorrhizal colonization by up to 29% . There- fore, the use of AMF inocula could be of importance to smallholder farmers in SSA who often farm on low fertility soils and have minimal or no access to mineral fertilizers.
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There was no statistically significant effect of N fertiliza- tion or any significant interactions between cropping system and sampling time on any of the targeted gene abundances. Therefore, we analyzed the impact of each biomass crop un- der specific harvest management on soil bacterial gene abun- dances (Table 2). Denitrifying (nosZ) gene copy abundances were affected by LUC; regardless of harvest or N manage- ment, mean nosZ gene copies were higher in miscanthus plots than in the corn–soybean rotation, and nirS : nosZ ra- tios were higher in the corn–soybean soils than in miscant- hus or switchgrass soils (p < 0.05) (Table 2). Under fall har- vesting management, biomass crop had no impact on total bacterial 16S rRNA gene copies or nirS gene copies. How- ever, leaving miscanthus biomass standing over winter until spring resulted in significantly higher 16S rRNA gene copies than observed in soils from fall-harvested biomass crops and significantly higher nirS gene copies than in fall-harvested switchgrass or the corn–soybean rotation (Table 2).
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1999; Wedin et al., 1995). Plant growth, organic matter input and turnover rates of different soil C components gives soils different δ 13 C and δ 15 N values. Progressive δ 13 C enrichment of organic matter that has been frequently observed could be related to a gradual shift in the relative contributions of plant components in the residual organic matter (Ehleringer et al., 2000). Polyacrylamide concentration was more easily quanti- fied in the Xeric Haplocalcid soils as compared to the Typic Torripsamment, Typic Kandiudult or Xeric Argialboll soils. Higher C concentrations in the Typic Torripsamment, Typic Kandiudult or Xeric Argialboll soils resulting from C input to soils from winter cover crops in addition to summer crops as compared to only summer crops growing in the Xeric Haplocalcid soil may have masked the lighter δ 13 C and δ 15 N that comprise the polyacrylamide molecule. PAM concentra- tions in soils measured by δ 13 C, correlated well between the two laboratories, but PAM concentrations in soils measured δ 15
The primary activity of many communities in Ogoniland is agriculture, 66% of households in the state are engaged in agricultural activities. According to the National Agricultural Sample Census 1993/94, 35% of holdings on land are possessed on ownership tenure, 17% on rented land (FACU, 1993). Annual planting of staple crops starts in the dry season (November-March) when floodwater must have subsided. After clearing the of land, women and children plant maize, yam, cassava or vegetables and oil palm from both the wild environment and plantations. Crops that are usually planted include cassava, cocoyam, plantain, banana, maize, yam, rice, sugar cane, and groundnut and to a limited extent cash crops such as oil palm and rubber. In addition to the staple crops, high priced vegetables such Telfaira spp., Amaranthus spp., waterleaf, melon and sweet potato are use as cover crops. Newly cleared forests are utilized for plantain and banana to take advantage of high organic matter status. Various crop combinations of yam/melon/maize/cassava, plantain/cocoyam telfaira and maize are arranged in relay forms. Plantain may start bearing at 8 months, but it is allowed up to 4-5 years a piece while banana could stay longer, up to 7 years. Crop plants such as Citrus species, kola, guava, mangoes, plantain, pawpaw, pear and pineapple may be planted around homesteads and as avenues along pathways or boundaries of farms (World Bank, 1992).
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Results: Copy numbers of bacteria and fungi significantly declined by 47.7 and 45.5%, respectively, upon American ginseng cropping over 3 years. A total of 66,391 classified sequences were obtained from high-throughput sequenc- ing analyses of 16S and 18S rRNA in six soil samples. A decline in bacterial diversity and an increase in fungal diversity were observed in the continuous cropping soils of American ginseng compared to those of traditional crops. Com- pared with soils used for traditional crops, the relative abundance of bacterial and fungal groups changed in soils subjected to continuous cropping with American ginseng.
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The amount of nitrogen (N) in the test plants shoot and root were higher in cover crops grown in the uncon- taminated soil than soils with different hydrocarbon content (Figure 1) suggesting that crude oil contamination reduced N uptake by plants. It has also been reported to influence water and nutrient uptake by plants, which is essential for plant growth . The reduction in shoot and root N of the legumes grown on the crude oil con- taminated soils observed in this study may be due to competition for available nutrients between the plants and microorganisms in soils . However, the severity of the effect of oil contamination on N uptake and plant growth varies with the plant species and the original soil properties . Our findings have revealed that the three plant species exhibited different responses to the hydrocarbon contents of the soil. For Pueraria phaseol- oides, the shoot and root N of plants grown on uncontaminated soil, and those on contaminated soil remedied with poultry manure and NPK increased rapidly within the first 6 weeks. However, there was no significant dif- ference in root N between poultry and NPK treated soils and the oil-contaminated soil (Figure 1). This indicates that N uptake by Pueraria phaseoloides was not affected by hydrocarbons within the range of 0.35 - 20.5 g∙kg −1 , although slight impact was noticed after 6 weeks of exposure. On the other hand, the shoot and root N contents
Globally, around 831 million hectares are affected by salts, of these 397 million (48%) have problems of salinity and 34 million (4.1%) sodicity problems (FAO, 2000). In Mexico salinization it is estimated to affect approximately 3.2% of the country, appearing significantly in the states of Sonora, Sinaloa, Tamaulipas, San Luis Potosi, Chiapas, Nuevo Leon, Oaxaca, Veracruz and Zacatecas (SEMARNAT, 2009) (see Figure 1) 10 (SEMARNAT, 2003), in those regions of the country the problem of salinity in irrigated areas of arid areas is associated, because the water is rich in salts and moreover there is no proper management of soil and water, It is resulting in soil degradation that affects the decrease in productivity and quality of crops (Bayuelo et al., 2003).
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Farmlands in the vicinity of Benue State University, Makurdi possess soils that are smooth textured but dry up rapidly when rains stop. Agricultural productivity in these soils is adversely affected as crops wilt away in extreme cases. There is need to ascertain measures that are required to improve crop production. A first line of approach is to characterize the soil through measurement of its properties such as the CEC and base saturation.
Puddling of the soil for rice production destroys soil structure and makes the growing of post-rice crops difficult. Straw management, direct sowing into the straw mulch and water management in these crops requires study. Significant effort has been, and is being put into growing legumes after rice. The choice of crop, legume or non-legume needs to be reconsidered as all the data to date shows very low yields from the major crops investigated so far namely, mungbean, soybean and peanut. The judicious use of herbicides and insecticides in these crops also requires investigation. .