Spatial scale of soil character is forefront in soil-scientific research, and the analysis of macropore reasonable sampling size becomes significant in studyinig on soil spatial variability. From the micro-structure of the soil, using digital image preparation and analysis technology, this paper described the soil macropore with rations, discussed the spatial structure of soil macropore on both...

Global positioning systems (GPS), yield monitors, various forms of remote sensing, new computer software, and variable rate technology are new tools available to producers. Intensive soil sampling and crop scouting methods that directly relate each sample or measurement with their geographical coordinates complement the new technological package. Soil testing is a diagnostic tool that adapts we...

A data-based resampling experiment is performed to estimate sampling errors of area-averaged soil moisture estimates due to spatial sampling by ground-based sensors. The data consists of high-resolution soil moisture images derived from the Polarimetric Scanning Radiometer (PSR/CX) sensor flown on an aircraft as part of the summer field experiment (SMEX04 — Soil Moisture Experiment 2004) in the...

Soil sample collection Nutrient content of soil can vary greatly by depth. The top 4-6 inches, the zone into which most fertilizer is placed and most crop residue is incorporated, often has much higher levels of organic matter, nitrogen (N), phosphorus (P), potassium (K) and micronutrients than the soil below. To accurately reflect overall nutrient availability a soil sample should be collected...

Spatial variability has a profound influence on a variety of landscape-scale agricultural issues including solute transport in the vadose zone, soil quality assessment, and site-specific crop management. Directed soil sampling based on geospatial measurements of apparent soil electrical conductivity (ECa) is a potential means of characterizing the spatial variability of any soil property that i...

Soil nitrate (NO3) tests are an integral part of nutrient management in annual crops. They help growers make field-specific nitrogen (N) fertilization decisions, use N more efficiently and, if necessary, comply with California’s Irrigated Lands Regulatory Program, which requires an N management plan and an estimate of soil NO3 from most growers. As NO3 is easily leached into deeper soil layers ...

Soil microbial communities are structured by biogeochemical processes that occur at many different spatial scales, which makes soil sampling difficult. Because soil microbial communities are important in nutrient cycling and soil fertility, it is important to understand how microbial communities function within the heterogeneous soil landscape. In this study, a self-organizing map was used to d...

Purpose of This Publication Knowledge of soil phosphorus (P) levels is an essential component of nutrient management planning for crop production and for tools that assess the risk of P loss from agricultural fields. Historically, soil P testing has been used to estimate P availability for crops and is now being used directly or as a component of P indices to assess the risk of P loss from fiel...