Cosmic Ray Neutron Sensing: Estimation of Agricultural Crop Biomass Water Equivalent

Earth Science; Soil Management; Water Management; Crop Nutrition; Nuclear; CRNS; Biomass Water Equivalent; Remote Sensing; Satellite Imager

Cosmic Ray Neutron Sensing: Estimation of Agricultural Crop Biomass Water Equivalent

This open access book provides methods for the estimation of Biomass Water Equivalent (BEW), an essential step for improving the accuracy of area-wide soil moisture by cosmic-ray neutron sensors (CRNS). Three techniques are explained in detail: (i) traditional in-situ destructive sampling, (ii) satellite based remote sensing of plant surfaces, and (iii) biomass estimation via the use of the CRNS itself. The advantages and disadvantages of each method are discussed along with step by step instructions on proper procedures and implementation

Cosmic Ray Neutron Sensing: Estimation of Agricultural Crop Biomass Water Equivalent

Earth Science; Soil Management; Water Management; Crop Nutrition; Nuclear; CRNS; Biomass Water Equivalent; Remote Sensing; Satellite Imager

The identification and significance of inputs to Anthrosols in North-West Europe

In recent years there has been a renewed interest in soils which are the result of past land management practices involving substantial additions of mineral and organic matter. However, there is still a substantial lack of detailed information on their formation. Anthrosols are distinguished by the presence of a deep top horizon and such soils were investigated at sites in Scotland, Denmark and The Netherlands. Field data and samples were collected from eight sites under arable cultivation, meadowland and woodland. Particle size distribution, pH, loss on ignition, ECEC, base saturation and total P were measured. Carbonaceous particles were identified through micromorphological analysis and the determination of O:C ratios using an electron microprobe. Despite the use of different inputs in recent centuries and different current land management, the resultant anthropogenic soils are remarkably similar in field and analytical properties. Nevertheless, subtle changes in particle size can be explained by parent material influences, material imported by farmers and by inputs by other processes such as by wind. The results from microprobe analysis demonstrate the importance of carbonaceous particles in storing phosphorus. Thus the inherent fertility of these Anthrosols can be explained in part by the application of carbonised material in the past

Estimation of medium-term soil redistribution rates in Ibadan, Nigeria, by using the 137 Cs technique

Soil erosion is a widespread and serious problem in Nigeria, West Africa. The 137 Cs technique is an alternative to field plots for generating data on medium-term soil redistri bution. It was tested in 2007 in Ibadan, Nigeria, which means the firs t time in the derived savanna. To analyse the vertical and spatial distribution of this nuclide in the soil, core samples were taken either randomly or along transects in an uncultivated and a cultivated site. The study showed an accumulation of 137 Cs near the soil surface and a slow decr ease with depth in the undisturbed site. The arable land was characterized by an almost uniform 137 Cs distribution within the ploughed layer. The reference inventory of 137 Cs determined on the uncultivated site was 569.3 ± 150.1 Bq m -2 ; the inventory of 137 Cs on the field ranged from 96.9 to 1494.4 Bq m -2 . Comparisons with the reference inventory showed smaller values for the upper slope and higher values for the lower slope of the cultivated site, wh ich indicated soil redistribution. The conversion of the inventories into quantitative data of erosi on and deposition by a proportion model revealed, for example, that about 148.5 t ha -1 yr -1 were eroded from the cropland in furrows leading downslope. The estimated results were comparable to erosion measurements made nearby. Hence, the 137 Cs technique is useful as a method to generate data on soil redistribution a nd therefore a tool for improved natural resource management in Nigeria

Using Cosmic-Ray Neutron Probes to Monitor Landscape Scale Soil Water Content in Mixed Land Use Agricultural Systems

With an ever-increasing demand for natural resources and the societal need to understand and predict natural disasters, soil water content (SWC) observations remain a critical variable to monitor in order to optimally allocate resources, establish early warning systems, and improve weather forecasts.However, routine agricultural production practices of soil cultivation, planting, and harvest make the operation andmaintenance of direct contact point sensors for long-termmonitoring challenging. In this work, we explore the use of the newly established Cosmic-Ray Neutron Probe (CRNP) and method to monitor landscape average SWC in a mixed agricultural land use systemin northeastAustria.Thecalibrated CRNP landscape SWC values compare well against an independent in situ SWC probe network (MAE = 0.0286m3/m3) given the challenge of continuous in situ monitoring from probes across a heterogeneous agricultural landscape. The ability of the CRNP to provide real-time and accurate landscape SWC measurements makes it an ideal method for establishing long-term monitoring sites in agricultural ecosystems to aid in agricultural water and nutrient management decisions at the small tract of land scale as well as aiding in management decisions at larger scales

AquaCrop: calibration of new crops

Extended core group meeting on AquaCro

Calibration and validation of the AquaCrop water productivity model for cassava (Manihot esculenta Crantz)

FAO’s water-driven crop growth simulation model, AquaCrop, was calibrated and validated for cassava (Manihot esculenta Crantz). Existing datasets, used in similar published works, were shared covering several years and regions (Colombia, Nigeria and Togo). Different varieties were tested for the case of Colombia and a single variety (TME-419) for Nigeria and Togo. Overall calibrated biomass simulations resulted in an R² of 0.96 and a RMSE of 1.99 tonne DM/ha. As for dry tuber yield estimates, it was not possible to find a single harvest index for the ensembled varieties given their varying characteristics and limited data per variety. However, for the TME-419 variety (Nigeria and Togo) calibrated root tuber simulations yielded and R² of 0.94 and a RMSE of 2.37 tonne DM/ha. A single crop-file was developed for different cassava varieties and agro-ecological regions, which can be applied with confidence to further study cassava related food security, water productivity, improved agronomic practices, etc