Effect of surface heterogeneity on hyper-resolution simulation of soil moisture

<p>Due to the land surface complexity, soil moisture immensely varies both spatially and temporally. However, the combined effects of land surface complexity and key hydrological processes (e.g., subsurface lateral flow) on fine-scale soil moisture heterogeneity remain elusive due to the scarcity of observations. Benefit from improvements in hyper-resolution land surface modeling, it provides an unprecedented opportunity to investigate the fine-scale soil moisture heterogeneity over a large region. Here, we use the Conjunctive Surface-Subsurface Process model version 2 (CSSPv2), which considers subsurface lateral flow, to perform hyperresolution (100-m) simulations over ten selected regions with different climate. We find that the heterogeneities of vegetation, soil texture, precipitation or their combinations increase soil moisture heterogeneity significantly (p<0.01). If only the topography heterogeneity presents, subsurface lateral flow increases the soil moisture heterogeneity significantly (p<0.01). However, the effect of subsurface lateral flow has been reduced by combining topography heterogeneity with other surface heterogeneities, with a few regions showing decreased soil moisture heterogeneity mainly because of the combined effect of subsurface lateral flow and soil texture heterogeneity. This study suggests that soil texture heterogeneity does not necessarily interact synergistically with physical processes (e.g., subsurface lateral flow) for increasing soil moisture heterogeneity, although they can increase the heterogeneity separately.</p>

Irrigation Effect on Evapotranspiration (in Absheron)

In the presented article, the results of the use of dispersed irrigation are considered. This method helps to reduce the ambient temperature, increase soil moisture, establish an optimal irrigation regime, reduce the need for water resources, prevent depression of photosynthesis of alfalfa agrophytocenosis under Absheron conditions. It is recommended to carry out dispersed irrigation on the soil surface at temperatures above 28 °C. The best results were obtained under the condition of the combined application of dispersed irrigation with sprinkling, especially in dry years.

Study on Climatic Variation and Its Effect on Vegetable Type Soybean Genotypes at Khumaltar, Lalitpur in the Last Ten Years

Soybean (Glycine max L. Merril) is widely grown in the mid hills as intercrop with maize or in paddy bunds, while it is gaining popularity as sole crop in terai and inner terai. Mean temperature at Khumaltar during soybean growing period was mostly fluctuating; but we observed an increasing trend in temperature. Amount of rainfall was not changed dramatically but number of rainy days was decreased during study period. Rainfall during germination time increase soil moisture which also increase germination and found higher early stand. Days from sowing to 50% flowering and 90% maturity were short in the case of higher minimum temperature and low rainfall. Among the genotypes, AGS-377, AGS-378, AGS-379 and Tarkari Bhattmas-1 were more sensitive. However, seed yield decreased in the case of higher temperatures and low rainfall. Cool night temperatures and high moisture increased disease incidence in soybean which, eventually reduced yield. In last three years, plant suffered from moisture stress during early vegetative stage and high moisture during late vegetative stage which reduced seed yield and seed weight. In conclusion, we found that genotypes like AGS- 360, Sathiya and Tarkari Bhatmas-1 are very sensitive to climatic variation.

The Construction and Configuration of Anasazi Pebble-Mulch Gardens in the Northern Rio Grande

Rio Grande Anasazi in the fourteenth and fifteenth centuries A.D. mulched hundreds of garden-sized plots with pebbles to increase soil moisture, reduce erosion, extend the growing season, and increase crop yields. This paper reports on the construction and configuration of pebble-mulch gardens in New Mexico, focusing particularly on those in the Galisteo Basin. Surfaces adjacent to these gardens were scraped and pits were excavated to collect gravel, which was placed over garden surfaces in layers 5 to 11 cm thick. Gardens averaged 15 x 23 m in size, although both size and shape were highly variable, and they collectively covered an area of 41,000 m2 Although this unique agricultural strategy has been shown to be effective, construction was limited to sites with natural gravel deposits, pebbled surfaces inhibited the recycling of crop wastes, and such gardens never became as widely used as more traditional field forms.