نتایج جستجو برای: soil nutrient

تعداد نتایج: 238772  

2003
Alfred E. Hartemink R. M. Bourke Alfred Hartemink

Alfred Hartemink is a soil scientist at ISRIC in Wageningen. Prior to his current position he was lecturer in soil science at the University of Technology in Papua New Guinea. He holds an MSc in soil science from Wageningen Agricultural University, and has worked as a soil surveyor and soil fertility specialist in Tanzania, Zaire, Indonesia, and for ICRAF in Kenya. Dr Mike Bourke is an Adjunct ...

2014
Hao Li Weijia Leng Yibing Zhou Fudi Chen Zhilong Xiu Dazuo Yang

Soil nutrient is an important aspect that contributes to the soil fertility and environmental effects. Traditional evaluation approaches of soil nutrient are quite hard to operate, making great difficulties in practical applications. In this paper, we present a series of comprehensive evaluation models for soil nutrient by using support vector machine (SVM), multiple linear regression (MLR), an...

2007
Jay B. Norton

In dryland cropping systems, optimal yields require that nutrient supply matches the soil’s yield potential supported by available moisture. Conservation tillage systems that leave at least 30 percent of the soil surface covered by residue dramatically increase moisture retained in the soil compared to crop-fallow systems. This enables producers to plant two, three, or four consecutive crops, o...

2011
Sofie Sjögersten Alexander W. Cheesman Omar Lopez Benjamin L. Turner

Biogeochemical properties, including nutrient concentrations, carbon gas fluxes, microbial biomass, and hydrolytic enzyme activities, were determined along a strong nutrient gradient in an ombrotrophic peatland in the Republic of Panama. Total phosphorus in surface peat decreased markedly along a 2.7 km transect from the marginal Raphia taedigera swamp to the interior sawgrass swamp, with simil...

2011
S. Zandi

Abstract: Soil pH has a major effect on plant nutrient availability by controlling the chemical structure of the nutrient. Adjusting soil acidity or alkalinity improves soil nutrition without adding extra fertilizers. Soil nutrients needed by plants in the largest amount are referred to as macronutrients. In addition to macronutrients, plants also need trace nutrients and both macro and trace n...

Journal: :تحقیقات آب و خاک ایران 0
سیدحمیدرضا صادقی استاد/ دانشگاه تربیت مدرّس حسین خیرفام دانشگاه تربیت مدرس مهدی همایی دانشگاه تربیت مدرس بهروز زارعی دارکی دانشگاه تربیت مدرس

runoff production process is a key hydrological component illustrating watersheds health. water infiltration in soil is also one of the determinant factors on runoff generation for which many techniques were used to improve it. however, the role of microorganisms for the improvement of water infiltration in soil has been less considered. the present study therefore tried to investigate the effe...

2010
Sarah J. Richardson Duane A. Peltzer Robert B. Allen Matt S. McGlone

Leaf lifespan varies widely among plant species, from a few weeks to >40 years. This variation is associated with differences in plant form and function, and the distribution of species along resource gradients. Longer leaf lifespans increase the residence time of nutrients and are one mechanism by which plants conserve nutrients; consequently, leaf lifespan should increase within species with ...

2014
C. B. Chikere

The effect of growth medium and incubation time were investigated by determining the number of colonies that were visible on triplicate plates of three different media on daily intervals. The viable counts were significantly different between the three different media even after the first day and this continued for seven days. Colony counts on the three media reached their maximum on the third ...

Journal: :The Journal of ecology 2011
Pablo García-Palacios Fernando T Maestre Antonio Gallardo

Recent research has shown that biodiversity may has its greatest impact on ecosystem functioning in heterogeneous environments. However, the role of soil heterogeneity as a modulator of ecosystem responses to changes in biodiversity remains poorly understood, as few biodiversity studies have explicitly considered this important ecosystem feature.We conducted a microcosm experiment over two grow...

2014
Kadri Koorem Antonio Gazol Maarja Öpik Mari Moora Ülle Saks Annika Uibopuu Virve Sõber Martin Zobel

Small-scale heterogeneity of abiotic and biotic factors is expected to play a crucial role in species coexistence. It is known that plants are able to concentrate their root biomass into areas with high nutrient content and also acquire nutrients via symbiotic microorganisms such as arbuscular mycorrhizal (AM) fungi. At the same time, little is known about the small-scale distribution of soil n...

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