scholarly journals ESPÉCIES DE UROCHLOA AFETAM DIFERENCIALMENTE A DISPONIBILIDADE DE FÓSFORO NO SOLO

2017 ◽  
Vol 13 (2) ◽  
pp. 34-40
Author(s):  
Moniki Campos Janegitz
Keyword(s):  
Cover Crops ◽  
Dry Matter ◽  
Control Treatment ◽  
P Availability ◽  
Initial Growth ◽  
Soil P ◽  
Soil P Availability ◽  
P Concentration ◽  
Microbial P

Species of the genusUrochloaare promising as cover crops inno tillagesystemsas a strategy to improve phosphorus availability and recyclingin the soil. The objective of this work was to evaluate the effectiveness of ruzigrassspeciesin enhancing soil-Pavailability. The experiment was conducted in a greenhouse in pots with soil,with five treatments: Urochloa brizanthacv. Marandu, U. decumbens, U. humidicolaandU.ruziziensis, plus one control treatment without Urochloa cultivation. The Urochloaplants were grown in PVC potsof 12.6 L and 50 days after emergence,dry matteryield, P concentration andP accumulation were evaluated. The soil wasseparatedinto rhizosphere and bulk soil and used to determination of P availability, microbial P and pH. Urochloas increased phosphorus availabilityand soil pH. U. ruziziensisshowed higher initial growth, higher dry matter yieldand higher P uptake.There was no differencebetweenspecies as toP concentrations in the plantand microbial P insoil. U. ruziziensiswas the species resulting inthe lowest level of soil P available,similar toU. humidicola.Cultivation of Urochloas increases thesoilphosphorus availability and changesitschemical characteristics. Comparingthe species studied, U. ruziziensiswould bethe best to improve soil P availability and cycling inthesoil.

scholarly journals Global patterns and drivers of soil total phosphorus concentration

2021 ◽  
Vol 13 (12) ◽  
pp. 5831-5846
Author(s):  
Xianjin He ◽  
Laurent Augusto ◽  
Daniel S. Goll ◽  
Bruno Ringeval ◽  
Yingping Wang ◽  
...  
Keyword(s):  
Parent Material ◽  
Phosphorus Concentration ◽  
Mean Annual Temperature ◽  
P Availability ◽  
Soil P ◽  
Soil P Availability ◽  
P Concentration ◽  
Organic Carbon Concentration ◽  
Global Patterns ◽  
Total P

Abstract. Soil represents the largest phosphorus (P) stock in terrestrial ecosystems. Determining the amount of soil P is a critical first step in identifying sites where ecosystem functioning is potentially limited by soil P availability. However, global patterns and predictors of soil total P concentration remain poorly understood. To address this knowledge gap, we constructed a database of total P concentration of 5275 globally distributed (semi-)natural soils from 761 published studies. We quantified the relative importance of 13 soil-forming variables in predicting soil total P concentration and then made further predictions at the global scale using a random forest approach. Soil total P concentration varied significantly among parent material types, soil orders, biomes, and continents and ranged widely from 1.4 to 9630.0 (median 430.0 and mean 570.0) mg kg−1 across the globe. About two-thirds (65 %) of the global variation was accounted for by the 13 variables that we selected, among which soil organic carbon concentration, parent material, mean annual temperature, and soil sand content were the most important ones. While predicted soil total P concentrations increased significantly with latitude, they varied largely among regions with similar latitudes due to regional differences in parent material, topography, and/or climate conditions. Soil P stocks (excluding Antarctica) were estimated to be 26.8 ± 3.1 (mean ± standard deviation) Pg and 62.2 ± 8.9 Pg (1 Pg = 1 × 1015 g) in the topsoil (0–30 cm) and subsoil (30–100 cm), respectively. Our global map of soil total P concentration as well as the underlying drivers of soil total P concentration can be used to constraint Earth system models that represent the P cycle and to inform quantification of global soil P availability. Raw datasets and global maps generated in this study are available at https://doi.org/10.6084/m9.figshare.14583375 (He et al., 2021).

scholarly journals Ruzigrass affecting soil-phosphorus availability

2013 ◽  
Vol 48 (12) ◽  
pp. 1583-1588 ◽  
Author(s):  
Alexandre Merlin ◽  
Zhenli Li He ◽  
Ciro Antonio Rosolem
Keyword(s):  
Cover Crops ◽  
Cropping System ◽  
Phosphorus Availability ◽  
Phosphorus Fertilization ◽  
P Availability ◽  
P Fertilization ◽  
Rock Phosphates ◽  
P Fractionation ◽  
Soil P ◽  
Soil P Availability

The objective of this work was to evaluate the effectiveness of ruzigrass (Urochloaruziziensis) in enhancing soil-P availability in areas fertilized with soluble or reactive rock phosphates. The area had been cropped for five years under no-till, in a system involving soybean, triticale/black-oat, and pearl millet. Previously to the five-year cultivation period, corrective phosphorus fertilization was applied once on soil surface, at 0.0 and 80 kg ha-1 P2O5, as triple superphosphate or Arad rock phosphate. After this five-year period, plots received the same corrective P fertilization as before and ruzigrass was introduced to the cropping system in the stead of the other cover crops. Soil samples were taken (0-10 cm) after ruzigrass cultivation and subjected to soil-P fractionation. Soybean was grown thereafter without P application to seed furrow. Phosphorus availability in plots with ruzigrass was compared to the ones with spontaneous vegetation for two years. Ruzigrass cultivation increased inorganic (resin-extracted) and organic (NaHCO3) soil P, as well as P concentration in soybean leaves, regardless of the P source. However, soybean yield did not increase significantly due to ruzigrass introduction to the cropping system. Soil-P availability did not differ between soluble and reactive P sources. Ruzigrass increases soil-P availability, especially where corrective P fertilization is performed.

Decreases in soil P availability are associated with soil organic P declines following forest conversion in subtropical China

CATENA ◽  
2021 ◽  
Vol 205 ◽  
pp. 105459
Author(s):  
Liuming Yang ◽  
Zhijie Yang ◽  
Xiaojian Zhong ◽  
Chao Xu ◽  
Yanyu Lin ◽  
...  
Keyword(s):  
Forest Conversion ◽  
P Availability ◽  
Organic P ◽  
Subtropical China ◽  
Soil P ◽  
Soil P Availability

The use of biologically based phosphorus fractions to evaluate soil P availability in reduced P-input paddy soils

2018 ◽  
Vol 34 (3) ◽  
pp. 326-334 ◽  
Author(s):  
J. Yuan ◽  
L. Wang ◽  
S. Wang ◽  
Y. Wang ◽  
H. Wang ◽  
...  
Keyword(s):  
Phosphorus Fractions ◽  
Paddy Soils ◽  
P Availability ◽  
Soil P ◽  
Soil P Availability

Using tree rings to reconstruct changes in soil P availability – Results from forest fertilization trials

2019 ◽  
Vol 54 ◽  
pp. 11-19 ◽  
Author(s):  
Martin Kohler ◽  
Jörg Niederberger ◽  
Adrian Wichser ◽  
Peggy Bierbaß ◽  
Thomas Rötzer ◽  
...  
Keyword(s):  
Tree Rings ◽  
P Availability ◽  
Forest Fertilization ◽  
Soil P ◽  
Soil P Availability

Benefits of winter legume cover crops require early sowing

2008 ◽  
Vol 59 (12) ◽  
pp. 1156 ◽  
Author(s):  
A. Gselman ◽  
B. Kramberger
Keyword(s):  
Cover Crops ◽  
Dry Matter ◽  
Control Treatment ◽  
N Fixation ◽  
Sowing Time ◽  
Mineral N ◽  
Late Autumn ◽  
Legume Cover Crops ◽  
Winter Cover ◽  
Winter Cover Crops

Winter cover crops are beneficial, especially legumes that can supply nitrogen (N) to the next crop. The purpose of this study, involving separate experiments carried out at 2 different locations in north-eastern Slovenia, was to determine the most appropriate sowing time (early, early autumn SD1; late, mid autumn SD2; very late, late autumn SD3) for winter legumes (Trifolium subterraneum L., T. incarnatum L., T. pratense L., and Vicia villosa Roth) for the optimal yield of beneficial dry matter and soil N cycling. The control treatment used Lolium multiflorum Lam. For legume cover crops in SD1, from 915.0 (T. subterraneum) to 2495.0 (V. villosa) kg herbage dry matter yield (HDMY)/ha, 52.3 (T. pratense) to 148.4 (T. incarnatum) kg accumulated N (AN)/ha, and 14.5 (T. pratense) to 114.5 (T. incarnatum) kg symbiotically fixed N (Nsymb)/ha was obtained to the end of autumn. Until the spring ploughing-in, which was before maize sowing, legume cover crops in SD1 yielded 1065.0 (T. subterraneum) to 4440.0 (T. incarnatum) kg HDMY/ha, 74.9 (T. subterraneum) to 193.0 (V. villosa) kg AN/ha, and 4.7 (T. subterraneum) to 179.0 (V. villosa) kg Nsymb/ha. All parameters in SD2 were significantly lower than in SD1, whereas the SD3 sowing was not suitable for the legumes. The benefits of legume winter cover crops with regard to symbiotic N fixation were achieved only by early sowing; however, the amount of soil mineral N in late autumn and in early spring was decreased under L. multiflorum more than under the legumes.

Interpretation of a single-point P buffering index for adjusting critical levels of the Colwell soil P test

Soil Research ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 55 ◽  
Author(s):  
P. W. Moody
Keyword(s):  
Buffer Capacity ◽  
Soil Phosphorus ◽  
Single Point ◽  
Maximum Yield ◽  
P Value ◽  
P Availability ◽  
Soil P ◽  
P Concentration ◽  
Soil P Test ◽  
Rate Of Increase

Soil phosphorus (P) buffer capacity is the change in the quantity of sorbed P required per unit change in solution P concentration. Because P availability to crops is mainly determined by solution P concentration, as P buffer capacity increases, so does the quantity of P required to maintain a solution P concentration that is adequate for crop demand. Bicarbonate-extractable P using the Colwell method is the most common soil P test used in Australia, and Colwell-P can be considered to estimate P quantity. Therefore, as P buffer capacity increases, the Colwell-P concentration required for maximum yield also increases. Data from several published and unpublished studies are used to derive relationships between the ‘critical’ Colwell-P value (Colwell-P at 90% maximum yield) and the single-point P buffer index (PBI) for annual medics, soybean, potato, wheat, and temperate pasture. The rate of increase in critical Colwell-P with increasing PBI increases in the order: temperate pasture < medics < wheat < potato. Indicative critical Colwell-P values are given for the 5 crops at each of the PBI categories used to describe soil P buffer capacity as it increases from extremely low to very high.

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