Role of land set-up systems on soil (Physicochemical) conditions

Land reclamation and drainage networks represent one of the most ancient human modifications of the Italian soilscape, where tailored land set-up systems were developed in agro-and forest-ecosystems in three millennia of man’s activity. Most of once manually maintained land settings are currently scarcely working or even disappeared because of the cost needed for their mainte-nance and the advent of mechanization that have simplified the field organization. The scarce attention to the soil experienced in the last decades, has accelerated soil erosion and flooding events, which entailed high costs in terms of money and human lives, but also caused reduction of soil thickness, water holding capacity, and fertility. In view of a sustainable agriculture, it is mandatory to assess the role of land set-up systems, which for centuries have been key in protecting soil from erosion, but also in increasing soil fertility. Such an effort cannot be made without considering the different pedo-climatic conditions and land uses of the Italian ter-ritory, which is different with respect to the past because of the multiple transformations made to favour the mechanization of agriculture. In this review we discuss the main effect of Italian land settings on the soilscape and on soil physicochemical condi-tions. Since land settings were developed centuries ago, detailed information about their effect on specific soil parameters is scarce in the scientific literature; thus, in some case, we provide information gathered in places where land set-up systems are still present. mm

Crop models and their use in assessing crop production and food security: A review

Agriculture is directly related to food security as it determines the global food supply. Research in agriculture to predict crop productivity and losses helps avoid high food demand with little supply and price spikes. Here, we review ten crop models and one intercomparison project used for simulating crop growth and productivity under various impacts from soil–crop–atmosphere interactions. The review outlines food security and production assessments using numerical models for maize, wheat, and rice production. A summary of reviewed studies shows the following: (1) model ensembles provide smaller modeling errors compared to single models, (2) single models show better results when coupled with other types of models, (3) the ten reviewed crop models had improvements over the years and can accurately predict crop growth and yield for most of the locations, management conditions, and genotypes tested, (4) APSIM and DSSAT are fast and reliable in assessing broader output variables, (5) AquaCrop is indicated to investigate water footprint, quality and use efficiency in rainfed and irrigated systems, (6) all models assess nitrogen dynamics and use efficiency efficiently, excluding AquaCrop and WOFOST, (7) JULES specifies in evaluating food security vulnerability, (8) ORYZA is the main crop model used to evaluate paddy rice production, (9) grain filling is usually assessed with APSIM, DAISY, and DSSAT, and (10) the ten crop models can be used as tools to evaluate food production, availability, and security

Designing, modeling, and evaluation of improved cropping strategies and multi-level interactions in intercropping systems in the North China Plain

Adjusting cropping systems in order to increase their efficiency is a global issue. High yield and sustainability are the catchphrases of production in the 21st century, and agricultural production has to solve the balancing act between ecology and economy. Therefore, the requests for farmers, consultants and researchers are rising, and production modes are changing. Nevertheless, solutions have to be detected spatially explicit and locally adapted and accepted in order to be implemented successfully. Taking the North China Plain as an example, the productivity of arable land needs to be further increased by applying strategies to reduce or avoid negative environmental effects. Further yield increases are not possible by increasing input factors like N-fertilizer or irrigation water as N-fertilizer rates are extremely high and irrigation water is limited. However, yield increases might be possible by developing improved cropping strategies operated by cropping designs. Taking modeling and simulation tools into account back up the acceleration of research attainments and the understanding of cropping systems. The present thesis embraces the designing and modeling of such a potential cropping system, to wit strip intercropping. Thus, the main goals of the study were to analyze, design, evaluate, and in the end model intercropping. Intercropping systems are complex systems which strongly need to be designed and evaluated carefully in order to fulfill the premises of ecological and economical efficiency as well as sustainability. Multi-level interactions have to be weighted and taken into regard for evaluating datasets applicative for modeling and simulating intercropping. The main results of the study indicated, that traditional cropping systems like intercropping are widespread in China, where approximately one third of arable land is under intercropping. Reviewing cereal intercropping systems in China, the four agro-ecological regions ?Northeast and North?, the ?Northwest?, the ?Yellow-Huai River Valley? and the ?Southwest? could be classified, distinguished and described. Intercropping offers a great variation of species combination, benefits as well as challenges for cropping systems design and farmers. Carefully balanced between facilitation and competition, intercropping bears the potential of increased yield and yield stability, income security, resource use efficiency and biodiversity. Intercropping gives evidence about traditional cropping systems with the potential for future production systems under the paradigm of sustainability. Further, results from conducted field experiments indicated that border effects are the key component of intercropping performance. Nevertheless, analyzing strip intercropping statistically has peculiarities as they lack in randomization because the cropping system imposes alternating strips. Thus, spatial variability and its effect on yield were regarded differently within a geo-statistical analysis. In addition to the geo-statistical analysis, the crop growth modeling approach paid tribute to monocropping effects as well as to field border effects occurring in strip intercropping systems. Further on a model-based approach was tested to quantify multi-level interactions with special regard to changing microclimatic conditions and to optimize intercropping systems from an agronomical point of view. In comparison to other interspecific competition modeling approaches, a shading algorithm was evaluated and implemented into the process-oriented crop growth model DSSAT in order to simulate competition for solar radiation. More common in modeling mixed intercropping, a modified Beer?s law subroutine has been used instead, e.g. in APSIM. APSIM and DSSAT were compared by modeling the conducted field trials. As a result, the Beer?s law approach was not capable to model strip intercropping. In contrast, the modeling with a changed DSSAT model showed that applying a simple shading algorithm that estimated the proportion of shading in comparison to the monocropping situation and in dependency from neighboring plant height seems to be a promising approach. The results indicated that competition for solar radiation in those systems is a driving force for crop productivity but neither the most dominant nor the one and only. Resource distribution and allocation in space and time seems to be more important than the total amount of resources. Those effects have to be taken into account when simulating interspecific competition.Definiert als der Anbau von zwei oder mehr Feldfrüchten auf der gleichen Fläche und innerhalb der gleichen oder einer sich überlappenden Vegetationsperiode, bietet Intercropping eine große Bandbreite an Kombinationsmöglichkeiten von Feldfrüchten, verbunden mit vorteilhaften und nachhaltigen Effekten für die jeweiligen Kulturarten. Intercropping ist aber gleichzeitig eine Herausforderung für jeden Landwirt und stellt hohe Ansprüche an die Gestaltung des jeweiligen Produktions- oder Anbausystems. Intercropping ist in China weit verbreitet. Schätzungen zufolge wird Intercropping auf rund einem Drittel der gesamten Anbaufläche praktiziert. Intercropping gilt als ein Anbausystem, welches bei geringerem Betriebsmitteleinsatz höhere Erträge oder Gewinne erzielt, verglichen mit den ausgedehnten Monocropping Systemen moderner Agrar-Industriebetriebe. Damit belegt Intercropping, dass in traditionellen Anbausystemen ein Potential für zukünftige und nachhaltige Produktionssysteme schlummert. Um diesen Paradigmen und um politischen, sozialen und ökonomischen Prämissen gerecht zu werden, muss die Agrarforschung Lösungen und Strategien für angepasste Produktionssysteme bereitstellen ? und das in immer kürzeren Zeitspannen. Der Einsatz von computergestützten Pflanzenwachstumsmodellen, mit deren Hilfe komplexe Anbausysteme regional und überregional, sowie über längere Zeiträume hinweg simuliert und analysierte werden können, hat sich dabei als wertvoll erwiesen. Wie Intercropping Systeme gestaltet werden müssen und welche Probleme dabei auftauchen, welche Datengrundlage für eine Modellierung benötigt wird und welche systemimmanenten Interaktionen berücksichtig werden müssen, sind Gegenstand der vorliegenden Dissertation. Allerdings gestaltet sich die statistische Auswertung von speziell Strip Intercropping als schwierig, da Intercropping-Versuche aufgrund der zwangsläufig streifenförmigen Anordnung nicht randomisiert werden können. Intercropping bedarf also einer räumlichen Betrachtungsweise, um ertragsrelevante Effekte adäquat abzuschätzen und statistisch abzusichern. Deshalb wurden die Versuche geostatistisch ausgewertet und mehrere räumliche Modelle evaluiert und getestet, um die Modellgüte zu verbessern. Nicht nur die statistische Auswertung von Intercropping ist diffizil, auch die Datengrundlage von Intercropping in China ist lückenhaft. Im Vergleich zu anderen Ländern wie beispielsweise Indien oder Teilen Afrikas, wo Intercropping gängige Praxis ist, scheint die Dokumentation und Erforschung von Intercropping Systemen in China Nachholbedarf zu haben. In einer Literaturstudie wurde deshalb ein erster Versuch unternommen, China in agro-klimatische Regionen hinsichtlich ihres Potentials und ihrer Verbreitung von Getreide betonten Intercropping Systemen einzuteilen. In einer zweiten Literaturstudie wurde dargestellt, welche Modelle für Intercropping bereits evaluiert, kalibriert und validiert wurden. Exemplarisch für ein prozess-orientiertes Pflanzenwachstumsmodell, welches multiple Anbausysteme und deren Konkurrenz um Sonnenlicht mithilfe des Beer-Lambert?schen Gesetzes simuliert, wurde APSIM gewählt. Dieser in der Forschung recht gängige Ansatz wurde mit dem in der vorliegenden Dissertation evaluierten, getesteten und in DSSAT implementierten Beschattungs-Algorithmus verglichen. Mit dem DSSAT Modell war es bislang nicht möglich, Intercropping zu simulieren. Es zeigte sich, dass es mit einem modifizierten Beer-Lambert?schen Gesetz nicht möglich war, Strip Intercropping adäquat zu simulieren. Unter der Voraussetzung, dass es im Strip Intercropping einen Gewinner und einen Verlierer gibt, das heißt, dass eine Kulturart mehr Sonnenlicht erhält als im Monocropping und eine andere dafür weniger, ist der Beer-Lambert?sche Ansatz viel versprechend und verwendbar. Die Kompensationsfähigkeit einer Fruchtart kann jedoch nicht simuliert werden, ebenso keine Ertragssteigerung der im System dominanten Fruchtart. Im Gegensatz dazu zeigte sich, dass der Beschattungs-Algorithmus, der in DSSAT integriert wurde, beide Systeme ? Intercropping und Monocropping ? simulieren konnte. Allerdings wurde in diesem Ansatz zusätzlich berücksichtig und getestet, dass Konkurrenz um solare Einstrahlung nicht die einzig bestimmende ist. Der Beschattungs-Algorithmus konnte zwar einen Teil des Ertragszuwachses im Intercropping erklären beziehungsweise simulieren, allerdings erst unter Berücksichtigung mikroklimatischer Effekte. Der Allokation von Pflanzenwachstumsfaktoren in Raum und Zeit kommt in Intercropping Systemen eine größere Rolle zu als deren absolute Höhe oder Menge. Solche Effekte müssen berücksichtig werden, um die Modellierung von Strip Intercropping weiterhin zu verbessern und Strip Intercropping Systeme zu optimieren

Measuring, modelling and managing gully erosion at large scales: A state of the art

Soil erosion is generally recognized as the dominant process of land degradation. The formation and expansion of gullies is often a highly significant process of soil erosion. However, our ability to assess and simulate gully erosion and its impacts remains very limited. This is especially so at regional to continental scales. As a result, gullying is often overlooked in policies and land and catchment management strategies. Nevertheless, significant progress has been made over the past decades. Based on a review of >590 scientific articles and policy documents, we provide a state-of-the-art on our ability to monitor, model and manage gully erosion at regional to continental scales. In this review we discuss the relevance and need of assessing gully erosion at regional to continental scales (Section 1); current methods to monitor gully erosion as well as pitfalls and opportunities to apply them at larger scales (section 2); field-based gully erosion research conducted in Europe and European Russia (section 3); model approaches to simulate gully erosion and its contribution to catchment sediment yields at large scales (section 4); data products that can be used for such simulations (section 5); and currently existing policy tools and needs to address the problem of gully erosion (section 6). Section 7 formulates a series of recommendations for further research and policy development, based on this review. While several of these sections have a strong focus on Europe, most of our findings and recommendations are of global significance.info:eu-repo/semantics/publishedVersio

Desertification assessment and future scenarios in the context of the climate change influence in Lebanon: planning for restoration activities and hydrological modeling

The purpose of this study was to assess desertification and to study the effects of land use change and climate change on hydrological variables in El Asi-Orontes watershed (Lebanon). This work presents a validated model to map land capability at a scale of 1:20,000 for El-Hermel District (Lebanon). The model was validated through field work and it indicates a good overall accuracy of 89%. The comparison between the zoning map already produced for the area of influence of Hermel city and the land capability map demonstrates a high risk of desertification because the zoning map doesn’t respect the capability of lands. We have also applied a hydrological model (WiMMed) in the study region in 2005 and 2013 to describe how land use change would affect the hydrological parameters. This study found that the land use change from 2005 to 2013 has negative effects on the hydrological characteristics of this watershed decreasing the infiltration capacity and the soil moisture of second layer in this area. Based on the results of the simulations, it can be concluded that in term of runoff low differences was registered in all seasons between 2005 and 2013. An attempt has been made to compare the current hydrological variables of the study area (infiltration, run-off, soil moisture of second layer) to the simulated variables in 2050 under 2 RCP future scenarios, RCP 2.6 and RCP8.5, assuming that that the future land use is the same as the current land use (2013 land use/land cover map). Under same land use conditions, a rise of temperature accompanied with a decrease of precipitation will result in a decrease of infiltration, soil moisture of second layer in all seasons, and run-off during spring and winter. All the hydrological variables within the study area are expected to have further decreases under RCP 8.5 compared to RCP2.6 for all seasons. However, the influence of land use change on soil moisture of second layer is much more significant when compared to climate variability and climate change. In conclusion, the land use patterns of the study region need to be modified according to identified land capability classes to sustain the remaining productive lands for future generations. This work was helpful to assess the stress on the land and hydrological states of the study region under different climatic scenarios, but to suggest restoration activities and to reduce the negative effects of land use change and climate change, more detailed studies are needed to suggest the correct land use type and to find a way to mitigate the effects of climate change in El Asi-Orontes watershed specifically, and semi-arid areas generally.El objetivo de esta tesis ha sido evaluar la desertificación y estudiar los efectos del cambio de uso de la tierra y el cambio climático en las variables hidrológicas de la cuenca de El Asi- Orontes (Líbano). En este trabajo se presenta un modelo validado para cartografiar la capacidad y aptitud de uso de la tierra, a una escala de 1:20.000, para el distrito de Hermel (Líbano). El modelo fue validado a través del trabajo de campo, mostrando una buena precisión general del 89%. La comparación entre el mapa de zonificación ya elaborado para el área de influencia de la ciudad de Hermel y el mapa de capacidad y aptitud de uso de la tierra demuestra un alto riesgo de desertificación ya que la planificación territorial de Hermel no está considerando el potencial y la capacidad de uso de la tierra. También se ha aplicado un modelo hidrológico (WiMMed) en la región de estudio en 2005 y 2013, para describir cómo el cambio de uso de la tierra ha afectado a los parámetros hidrológicos que definen la dinámica de la cuenca de El Asi-Orontes. Este estudio encontró que el cambio de uso de la tierra entre 2005 y 2013 tuvo efectos negativos sobre las características hidrológicas de esta cuenca disminuyendo la capacidad de infiltración y la humedad del suelo de la segunda capa en esta área. Con base en los resultados de las simulaciones, se puede concluir que en términos de escorrentía se registraron bajas diferencias en todas las estaciones entre 2005 y 2013. También se han comparado las variables hidrológicas actuales del área de estudio (infiltración, escorrentía, humedad del suelo de la segunda capa) con las variables simuladas en 2050 bajo 2 escenarios futuros, RCP 2.6 y RCP8.5, asumiendo que el uso futuro de la tierra es el mismo que el uso actual de la tierra (mapa de uso/cobertura de la tierra de 2013). Bajo las mismas condiciones de uso de la tierra, un aumento de la temperatura acompañado de una disminución de las precipitaciones resultará en una disminución de la infiltración, de la humedad del suelo de la segunda capa en todas las estaciones, y de la escorrentía durante la primavera y el invierno. Se espera que todas las variables hidrológicas dentro del área de estudio tengan disminuciones mayores bajo el escenario RCP8.5 en comparación con el RCP2.6 para todas las estaciones. Sin embargo, la influencia del cambio de uso de la tierra en la humedad del suelo de la segunda capa es mucho más significativa en comparación con la variabilidad y el cambio climático. En conclusión, los patrones de uso de la tierra de la región de estudio necesitan ser modificados de acuerdo a las clases de capacidad y aptitud de uso de la tierra identificadas para mantener las tierras productivas restantes para las generaciones futuras. Este trabajo fue útil para evaluar la presión ejercida sobre la tierra en relación a sus usos y los estados hidrológicos de la región de estudio bajo diferentes escenarios climáticos, pero para planificar actividades de restauración adecuadas y reducir los efectos negativos del cambio en el uso de la tierra y el cambio climático, se necesitan estudios más detallados para sugerir el tipo correcto de uso de la tierra y encontrar una manera de mitigar los efectos del cambio climático en la cuenca hidrográfica de El Asi-Orontes específicamente, y en las áreas semiáridas en general

Experimental approach for quantifying crop water use and pollutant loading from agricultural plot

Storm water runoff is the main contributor to non-point source (NPS) pollution in agricultural land. This issue is extremely important in tropical region due to its high intensity and frequent storms. The objectives of this study were to determine the crop coefficient of two vegetable crops – bittergourd (Mormordica Charantia) and chilli (Capsicum Annuum), investigate the mechanism of NPS pollutant transport and the influence of hydrologic regime on the pollutant loading. This study was conducted at the Modern Agriculture Centre in Kluang, Johor, from August 2013 to May 2014. A total of 86 rainfall events were recorded but only 52 storms had generated measurable runoff. Samples of runoff, soil water and groundwater were collected after every rainfall event and analysed for nutrient and sediment contents. Twenty-six reference evapotranspiration (ETo) models which were classified into four different groups were employed and their performance was ranked based on eight different statistical test. Penman model provide the best result in estimating ETo while the Schendel model tended to overestimate the observed pan ET. The limited parameters used in the temperature based group causes poor performance in predicting the ETo values. Crop coefficient (Kc) curves for both crops were developed as the ratio of actual ET measured by minilysimeters to the ET values of the best model. The Kc values for the bittergourd were 0.58, 0.88 and 0.69 while for chili were 0.58, 0.95 and 0.73 for the initial, mid and end growth stages, respectively. More runoff event was observed for the bittergourd as its growing period coincided with the North-East Monsoon. The average runoff-rainfall ratio is less than one percent due to the high hydraulic conductivity of the site. The concentrations of nutrients and sediments were very high with maximum Nitrite (NO2), Nitrate (NO3), Ammoniacal-Nitrogen (NH3-N), Phosphate (PO4), Total Nitrogen (TN), Total Phosphorus (TP), Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS) concentrations in the runoff were 0.385, 10, 4.2, 13.7, 27, 18, 190 and 15000 mg/l respectively. However, the calculated pollutant loading were low due to the remarkably small surface runoff volume. Soil water analysis at 15 and 60 cm soil depth shows a high Phosphorus (P) element leaching to the deeper depth even though P is less mobile. Nitrate concentration showed an increasing trend compared to other nutrients with a maximum of 1.7 mg/l at the end of the study period. The calibration and validation of the Root Zone Water Quality Model (RZWQM2) were carried out to model the leaching of NO3 to the groundwater. The results of this study can be applied to formulate more reliable water management schemes based on the water requirement of the vegetable crops and providing new information for controlling NPS pollution loading from agricultural activities

Evaluating the sustainability of urban agriculture projects

Evaluating the sustainability of urban agriculture projects. 5. International Symposium for Farming Systems Design (AGRO2015

Geographical information systems as a tool to explore land characteristics and land use : with reference to Costa Rica

An adequate inventory of land characteristics and land use is increasingly necessary to support agricultural land use planning, especially in view of the conflicting demands on scarce land resources. Fortunately new tools like GIS are being developed and adapted to support these inventories. Although GIS may be a useful tool for the storage and management of spatial data, its development is often "technology driven" and not directly focused on the applications. This thesis presents approaches to use GIS in the inventory and analysis of land characteristics and land use. The approaches are explored and illustrated for the perhumid tropical lowlands in the northeast of Costa Rica. More detailed studies are focused on the Neguev settlement located in these lowlands.In Chapter 2, a procedure is formulated to develop and select database structures for soil survey data. The procedure is based on a five step approach in which i) a data model is developed for the soil survey data, ii) alternative database structures are created, iii) possible queries are analyzed, iv) the efficiency of the database structures is evaluated on the basis of quantitative indicators, and v) the most appropriate database structure is selected. Applications are not always based on queries only. Therefore, the structure of the soil survey database is tested on the basis of a practical application: possible modelling approaches to deal with biocide leaching on the basis of the soil survey data. Biocide leaching is one of the main environmental problems in the Northern Atlantic Zone. A best possible assessment of the severity of the problem, from different perspectives, is needed for the various stakeholders. For the Atlantic Zone, one of the few readily available data sets comprises the soil survey data. To deal efficiently with the different approaches of users, the proposed soil information system needs to provide data at different levels of detail. Therefore, a rule base is developed for each of the hierarchical levels (mapping units, pedons, and soil horizons). The rule base includes decision rules for the generalization of data at a specific hierarchical level. Although aside from soil survey data, additional measurements may be necessary for many applications, soil survey data are useful to screen for potential risk areas and to select sites where additional measurements are most effective.Typically, the analysis of land use at a regional scale should be focused on its changes over time, but this is rarely done in a systematic way. In Chapter 3, the use of GIS to quantitatively describe land use dynamics is explored. Three different indicators for land use dynamics have been developed. The indicators include a singletime approach based on qualitative knowledge of the colonization history, Markov chains with soil type as a probability modifier, and Markov chains with a geographical analysis to stratify for polygon size, shape and neighbouring land covers.Often, users of GIS require very specific, disciplinary operations on geo-information that are not supported by GIS. These operations can be made available to the GIS through links with external models. In Chapter 4, structures and examples are given to link GIS with models dealing with the sustainability of agricultural production. A general structure for the GIS-model interface is presented and identifies six consecutive steps: i) geometry operations, ii) attribute operations, iii) data export from the GIS to the external model, iv) model run, v) data import from the model into the GIS, and, vi) visualisation or spatial analysis of the model results with the GIS. This structure is illustrated for a case study where a GIS is linked with a LP model for the analysis of alternative land use scenarios. The structure can be operationalized, using the abilities of many commercial software packages to develop user oriented applications.To explore the possibilities to reduce soil nutrient depletion in a settlement area, a GIS was linked with a model estimating soil nutrient depletion for land use systems and a LP model. The distribution of land use over different land units can be optimized with the LP model to minimize soil nutrient depletion in the settlement. This technique explores the geographical distribution of land utilization types to create a more sustainable basis for agriculture in the area. In contrast with traditional land use planning where land utilization types are matched with land units on the basis of maximizing present agricultural production, this approach focuses on long-term effects of land use and sustainability.To explore the trade offs between sustainability and economic objectives, different models and tools were integrated for the analysis of different land use scenarios for the Neguev settlement. Crop growth simulation and expert systems were used to describe alternative land use systems. A GIS was used for data storage, and the analysis and presentation of results. The optimization of land use was carried out by a LP model. Using a series of relevant land use scenarios, effects are studied of: (i) restrictions on biocide use; (ii) nutrient depletion as a negative contribution to farm income, and (iii) changes in capital availability. For the integration of models and tools, a modular approach is proposed, which is based on separate software packages and appropriate database structures. The methodology is particularly appropriate for interdisciplinary research, integrating socio-economic and agro-ecological data.In Chapter 5, the use of GIS databases and data needs for the analysis of land use and its sustainability is studied. Externally, land use can be affected by incentives and regulations. Data needs are studied and discussed for the analysis of regional production possibilities of maize, an analysis of sustainability indicators, and the possible contamination of ground and surface water with the commonly used nematicide Ethoprop. The different cases vary in their complexity and the level of detail required for the results. Data requirements change correspondingly. General inventories may already indicate which type of data collection is useful. Studies with a low level of detail must precede more detailed studies, while complex detailed studies could benefit from a change of scale, associated with a more generalized representation of data.Future challenges to incorporate the use of GIS in both disciplinary and interdisciplinary methodologies are recognized. This will require an integrated development of both GIS technology and applications. The ultimate challenge remains applying the proposed techniques to support the increasing demand for agricultural products and at the same time safeguarding the sustainability of the production and natural resources