نتایج جستجو برای: 30 cm and subsurface soil 30
تعداد نتایج: 16943251 فیلتر نتایج به سال:
A field experiment was conducted to evaluate the performance of locally developed combine equipment used for several agricultural operations at once in a silt clay loam soil texture. Three factors were used. The first is forward speed machinery unit, with three speeds: 2.98, 4.37, and 6.18 km h-1, second plowing depths, depths subsurface irrigation pipes 10/20, 15/25, 20/30 cm, third distances ...
A long term data acquisition effort of profile soil moisture is currently underway at 13 automatic weather stations located in southwestern France. In this study, the soil moisture measured in-situ at 5 cm is used to evaluate the normalised surface soil moisture (SSM) estimates derived from coarse-resolution (25 km) active microwave data of the ASCAT 5 scatterometer instrument (onboard METOP), ...
We investigated the effect of mulch on N cycling in a hardwood plantation of subtropical Australia by examining monthly in situ net N mineralization for 12 months and natural N abundance (δN) of soil and plants. Monthly net N mineralization ranged from –23.0 μg g soil (net immobilization) to 52.6 μg g soil across 12 sampling months and across both mulch and nonmulch treatments. There was a sign...
Abstract Nutrient stratification of no‐till managed soil can affect test analysis levels plant‐available phosphorus (P). Research has suggested sampling to different depths due acidity, but little work been conducted investigate any change recommendations for immobile nutrients. The objective this study was determine the depth that had greatest relationship with yield response fertilizer‐P. sam...
Brassicaceae seed meals produce ionic thiocyanate (SCN (-)), a bioherbicidal compound. This study determined the fate of SCN (-) in a field soil amended with seed meals of Sinapis alba, Brassica juncea, and Brassica napus and quantified crop phytotoxicity by monitoring carrot ( Daucus carota) emergence. Meals were applied at 1 or 2 t ha (-1), and soils were sampled to 35 cm for SCN (-). Maximum...
nitrogen use efficiency and life cycle of root nodules in alfalfa after different mineral fertilization and soil cultivation practices were studied. field trial was conducted in the institute of forage crops, pleven, bulgaria on leached chernozem subsoil type and no irrigation. the next treatments were tested: i) for fertilization as follows: n0p0k0 (control); n60p100k80 (an accepted technology...
Nitrogen use efficiency and life cycle of root nodules in alfalfa after different mineral fertilization and soil cultivation practices were studied. Field trial was conducted in the Institute of Forage Crops, Pleven, Bulgaria on leached chernozem subsoil type and no irrigation. The next treatments were tested: i) for fertilization as follows: N0P0K0 (control); N60P100K80 (an accepted technology...
We report the rapid acidification of forest soils in the San Bernardino Mountains of southern California. After 30 years, soil to a depth of 25 cm has decreased from a pH (measured in 0.01 M CaCl2) of 4.8 to 3.1. At the 50-cm depth, it has changed from a pH of 4.8 to 4.2. We attribute this rapid change in soil reactivity to very high rates of anthropogenic atmospheric nitrogen (N) added to the ...
The effects of 34 years cultivation on organic carbon content of the loess derived soils were studied in Golestan province, northern Iran. Soil organic carbon (SOC) showed significant decrease in most of cases. The minimum and maximum SOC decreases were 4 and 51.14 Mg C ha-1/30 cm for 34 years. In a few cases there was an increase in SOC up to 16.93 Mg C ha-1/30 cm over the period of 34 years i...
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