Open Access Minireview Article

Hydrostructural Pedology, New Scientific Discipline Allowing for Physical Modelling of ‘Green Water’ Dynamics in the Soil-Plant-Atmosphere System

Erik Braudeau; Hassan Boukcim; Amjad T. Assi, Rabi H. Mohtar

Journal of Agriculture and Ecology Research International, Page 1-8
DOI: 10.9734/JAERI/2018/43822

Using a new paradigm of soil characterization and modeling in agro environmental sciences, named hydrostructural pedology, we were able to show that the “green water” concept of agronomists corresponds exactly to the pedostructural water concept which was physically defined in this paradigm. The water in the pedostructure of soils is composed of two types of water, named micro and macro, nested one in the other. They are differentiated by their chemical potential related to their position in the pedostructure: inside primary aggregates or outside of them in the interpedal space. A fundamental physics of the pedostructural water could be developed within this new paradigm.  Finally, the soil medium can now be considered as the location in which the free water (named also blue water), coming from surface (rainfall, irrigation, etc.) and going down by gravity through the macro pore space of the soil, is partially absorbed by the pedostructure, and becomes then the ‘green water’ of the soil.  Soil green water is, in fact, the soil water reserve available to plant roots and subsequently transpired by the plants into the canopy. The soil-water model Kamel®, built according to this new paradigm, is the only model able to physically simulate the opposite dynamic cycles of these two kinds of water (blue and green) within the soil-plant-atmosphere system, their exchanges and equilibrium states according to time, at each depth of the pedon. Important implications about strategy of soil-water characterization, mapping and modeling are given for sustainable development and management of agricultural zones.

Open Access Original Research Article

Sweet Potato Varietal Evaluation Trial for Food Nutritional Values

Abonuusum Ayimbire, Abdul- Rahaman Saibu Salifu, Christina Abi Atinga, Delali Polycarp

Journal of Agriculture and Ecology Research International, Page 1-12
DOI: 10.9734/JAERI/2018/42623

Aim: To explore the nutrients, minerals, beta-carotene and total carotenoid contents of five sweet potato varieties viz., Agric orange flesh, Agric white, Red skin, Orange flesh and T.U. purple.

Study Design: The sweet potato vines at six week stage were cut into 1.2 m each and transplanted in parallel lines on the same 1.2 m x 2.6 m bed, spaced about 0.52 m from each other in Dukumah Garden. There were five such beds and vine cuttings transplanted in the same order on each bed.

Study Site: The study, which took four months, was conducted in the Dukumah Garden in Bolgatanga Municipality (10.7875°N, 0.8580°W) of the Upper East Region of Ghana.

Methodology: The sweet potatoes were harvested four months after transplanting on the same day. Samples of the various varieties were collected, parcelled, appropriately labelled and hand-delivered to the Food Chemistry Laboratory of Kwame Nkrumah University of Science and Technology for the analysis of proximate analysis (%), total carotenoids and beta-carotene concentrations in mg/g and concentrations of the minerals, namely magnesium (Mg), sodium (Na), potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) in mg/kg.

Results: All the five varieties of sweet potato were found to be nutritious. Protein content ranged from 3.82% in Agric white variety to 0.11% in Agric orange flesh. Fat content ranged from 4.84% in orange flesh variety to 1.74% in red skin. Crude fibre content was between 1.77% in Agric orange flesh and 0.10% in T.U. purple. Total carbohydrate varied from 23.2% in Agric orange flesh variety to 15.8% in Agric white one. Moisture was high in all the varieties, ranging from 75.78% in Agric white variety to 71.04% in Orange flesh one. The Orange flesh variety had the highest ash content of 1.56%. All the varieties contained high concentrations of Mg but low concentrations of Na and K. The highest concentration of Ca (8250.70±0.06 mg/kg) was recorded in T.U. purple. The concentrations of Fe in the sweet potato varieties decreased in the following order: T.U. purple>Red skin>Orange flesh>Agric orange flesh>Agric white. The highest (123.12±0.00 mg/kg) and the lowest (33.10±0.00 mg/kg) Zn concentration were recorded in the orange flesh and Agric white varieties, respectively. The concentration of beta-carotene (mg/kg) in five sweet potato varieties was in the following order: Agric orange flesh<<Agric white<Red skin<Orange flesh<T.U. purple.

Conclusion: The five varieties of sweet potato were found to be rich in proteins, total carbohydrates and fats. They were observed to vary in macro- and micronutrients, beta-carotene and total carotenoids contents. T.U. purple variety was identified to be the richest source of Ca and beta-carotene. Thus, the sweet potato varieties may be of considerable importance in ameliorating nutrient, mineral as well as beta-carotene malnutrition in poorly resourced areas of the developing countries.

Open Access Original Research Article

Dynamics of Carbon and Nutrients in a Successional Forest Sequence in the Mesopotamian Espinal (Argentina)

C. Mendoza, N. Ayala, M. Antivero, C. Italiano, E. Giardina, A. Di Benedetto

Journal of Agriculture and Ecology Research International, Page 1-8
DOI: 10.9734/JAERI/2018/44114

The Mesopotamian Espinal has been recently modified in several areas of Entre Ríos province (Argentina) due to the advance of the agricultural frontier, producing an important reduction in forest area. Inappropriate forest management had early transformed the native and primary forests into degraded or secondary forests. Deforestation and land abandonment have led to the development of a sequence of successional forest stages. The aim of this work was to assess the effects of forest succession changes on soil properties and nutrients contents of a successional forest sequence in the Mesopotamian Espinal (Argentina) which would be associated with livestock production. To reach proposed objectives, ten soil samples were collected from the depth of 0-10 (A-horizon) and 30-40 cm (B-horizon) from 4 sites in three forest successional sequence. An initial forest (IF) (approximately 20 years at the beginnings of this study), a secondary forest (SF) (mixed forest with trees of between 60 and 80 years old) and a mature forest (MF) with minimal signals of degradation were studied. Results showed soil texture changes during the successional forest process with higher clay and coarse sand but lower silt and fine sand values at the IF stage than MF state. In the same way, an increase in organic matter (as much in the humic- as in the fulvic-fraction) and in most nutrient (nitrogen, phosphorus, calcium, magnesium and potassium) were found. Data showed that whenever forest reach to mature state, soil quality indicators would explain part of the higher plant productivity.

Open Access Original Research Article

Sowed Pastures in the South-Eastern Romanian Plain

Kinan M. Kadir

Journal of Agriculture and Ecology Research International, Page 1-5
DOI: 10.9734/JAERI/2018/42907

The objective of this study was the identification of the mixtures with elite traits to  provide some high-quality fodders, in adequate quantity in the tilled areas sowed in large pastures. Previously, most farms in this area used to cultivate only alfalfa, which is the most important fodder crop in the area. Lately, pastures have been sown with mixtures of Graminaceae and Leguminous varieties, which have superior fodder values. This is possible as these varieties are better adapted to the natural conditions specific to the area. Three mixtures of perennial fodder varieties made of two Graminaceae crops (Dactylis glomerata andFestuca arundinaceea) and two leguminous crops (Medicago sativa and Trifolium repens-Ladino) were tested with different mixtures for the years 2016-2019. The results obtained in the first year of harvest (2016) characterised by the climatic conditions over the area showed that the average medium annual production of the three mixtures reached the value of 88.7 t/ha, and this was same as the yield obtained by only alfalfa fodder crop (M. sativa). The highest yield was achieved with the first two harvests resulting over 60% of  the total yield. The non-uniformity of the climatic factors during the vegetation period leads to a non-uniform distribution of the yield on reapings. Also, the yield obtained with the the third mixture was low (84 t/ha) as a consequence of the lower adjustment capability of white trefoil (T. repens) to the droughty climatic conditions.

Open Access Original Research Article

Assessing Different Irrigation Regimes Regarding Chlorophyll Content of the Sweet Bell Pepper

Ahmet Tezcan, G. Ece Aslan, Harun Kaman, Mehmet Can, Abdullah Sayic, Ufuk Gökçen, Hazel Ekizoğlu

Journal of Agriculture and Ecology Research International, Page 1-7
DOI: 10.9734/JAERI/2018/43845

Effective use of water is critically significant in the agriculture where water is most used. Many researchers indicate that at present and in the future, irrigated agriculture will have to take place under limited irrigation water available. Deficit irrigation, which aims efficient use of water, is becoming more predominant. Due to all these reasons, it is very important to find out the effect of the deficit irrigation on the plant growth. Photosynthesis is one of the physiological events that affect plant development. Chlorophyll plays an important role in photosynthesis process by absorbing sunlight and uses its energy to synthesise carbohydrates from CO2. The aim of this study is to determine the effect of different irrigation regimes on chlorophyll a and b contents of the sweet bell pepper. For this purpose, this study was carried out in a controlled 1 da glasshouse environment in the research area at Faculty of Agriculture, Akdeniz University. In the experiment four irrigation regimes (I100, I80, I60 and I40) were examined. Chlorophyll analysis of the sweet bell pepper was carried out according to the method of acetone extraction before and after irrigation following the fruit formation period. According to the experiment results, it was found out that chlorophyll degradation increases due to the aging of the plant leaves, therefore, the amount decreased. It was also found that this decrease in I40, which is the most stressful treatment, is much more evident than in other treatments.