Build up of soil phosphorus in coffee plantations of Karnataka overthree decades

2017 ◽  
Vol 45 (1) ◽  
Author(s):  
P. Shiva Prasad J.S. Nagaraja ◽  
S.A.Nadafand M. Violet D’ Souza
Keyword(s):  
Iron Oxides ◽  
Soil Analysis ◽  
Available P ◽  
Available Phosphorus ◽  
P Availability ◽  
Total Production ◽  
Data Set ◽  
Soil P ◽  
High Category ◽  
The Impact

<p>Karnataka is the largest coffee producing State in India contributing 72.3 per cent of the total production of the country. Arabica<br />Coffee is being cultivated in Karnatakain an area of 1.1 lakh ha and Robusta coffee in 1.2 lakh ha. Coffee growing soils are deep,<br />friable, rich in organic matter, high in potassium content, well drained and slightly acidic in reaction. These soils contain large<br />quantities of aluminium and iron oxides. Hence, phosphorus (P) availability in the Indian coffee growing soils is a constraint as<br />the aluminium and iron oxides fix the appliedphosphorus. Soil testing laboratories(STLs) of Coffee Board are rendering advisory<br />service to the growers based on soil analysis and classify the data into low, medium and high category. In order to know the impact<br />of the lime and fertilizer management on the soil available P status of the coffee growing soils of Karnataka, the soil-P data were<br />compiled and classified into different categories for the 3 districts, viz., Chikmagalur, Hassan and Kodagu for a period from 1980-<br />81 to 2015-16. The decade-wise data set on soil available phosphorus so obtained was analyzed and the changes occurred over a<br />period of time were assessed.The results indicated that over a period of thirty six years clear cut shift has taken place from low to<br />high category in the available P status of soils cropped to coffee. About 50per cent of the samples were low during 1980s while<br />this has reduced to 42 per cent during 1990s and further reduced to 23per cent during 2016. On the other hand the percentage of<br />samples under high category has gradually increased from 24 to 51.</p>

Effect of Soil Available Phosphorus Levels on Chickpea (Cicer arietinum L.) - Rhizobia Symbiotic Association

2020 ◽  
Author(s):  
Khadraji Ahmed ◽  
Bouhadi Mohamed ◽  
Ghoulam Cherk
Keyword(s):  
Cicer Arietinum ◽  
Available P ◽  
Phosphorus Concentration ◽  
Available Phosphorus ◽  
Symbiotic Association ◽  
P Deficiency ◽  
Soil P ◽  
P Content ◽  
Nodule Biomass ◽  
Soil Available P

Background: Growing chickpea (Cicer arietinum) plants is affected by several environmental constraints as osmotic stress and nutrients deficiency particularly phosphorus (P). For other legume species, it was confirmed that P deficiency affects negatively their rhizobial symbiosis. The purpose of this study was to assess the effect of soil available P level on chickpea-rhizobia symbiosis under field conditions at Oualidia region of Morocco. Methods: Ten farmers’ fields with different soil available P levels were considered to carry out this study based on samples of 10 plants per plot. Result: The results showed that the plants from soil 7, with the lowest pH and the highest available P level (23.52ppm), presented high shoot dry weight (38.3 g/plant). Meanwhile the soil 5 with the lowest available P content showed low plant growth. The shoot P content was positively linked to soil P level but nodule biomass showed an irregular variation with soil available P level. Furthermore, it was confirmed that adequate plant P nutrition results in high chickpea yield and it was the case for plants from soil 7 presenting a mean yield of 62 seeds per plant). Finally, strong correlation was noted between yield and phosphorus concentration in soil (r=0.94).

Responses of herbage yield and soil phosphorus fractions to phosphorus fertilisation on a degraded arid steppe

2018 ◽  
Vol 69 (8) ◽  
pp. 846 ◽  
Author(s):  
Dangjun Wang ◽  
Zhibin He ◽  
Zhen Zhang ◽  
Qingfeng Du ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Soil Phosphorus ◽  
Pot Experiment ◽  
Available Phosphorus ◽  
P Availability ◽  
Organic P ◽  
Soil P ◽  
Sheep Manure ◽  
Arid Steppe ◽  
Plant Yields ◽  
Phosphorus Fertilisation

Low plant-available phosphorus (P) in degraded arid steppes greatly limits plant yields. However, whether exterior P addition will improve the soil P availability and thus increase plant yield in these degraded arid steppes is still not certain. In the current study, a severely degraded arid steppe in Inner Mongolia, China, with soil-available P <5 mg/kg, was fertilised annually with chemical or manure P for two years (2014, dry year; 2015, wet year). There were six fertilisation treatments: 0, 30 kg P/ha, 60 kg P/ha, 90 kg P/ha, 4000 kg sheep manure/ha (equalling 16.4 kg P/ha) and 8000 kg sheep manure/ha (32.8 kg P/ha). A pot experiment with Stipa krylovii (the dominant plant species in the tested steppe) and five P application rates (0, 30, 60, 90 and 120 kg P/ha) was also conducted, under well-watered and nitrogen-fertilised conditions, using surface soils from unfertilised plots in the field. Results indicated that the tested soils had strong P adsorption capacity and weaker desorption capacity, and that the labile P fractions were quickly transformed into less labile fractions, reducing P availabilities. Overall, chemical P fertiliser resulted in the accumulation of Ca10-P and occluded P, whereas sheep manure resulted in the accumulation of moderately resistant organic P and highly resistant organic P. Phosphorus fertilisation was associated with an increase in plant P concentrations in both 2014 and 2015, and a low P rate (30 kg P/ha in the current study) was able to improve the aboveground biomass in both the field experiment in the wet year and the pot experiment under well-watered conditions. Thus, in degraded arid steppes, P fertilisation may be unnecessary in dry years. A low rate of P fertilisation is recommended in wet years to improve soil P status and steppe plant productivity.

scholarly journals Phosphate Adsorption Capacity and Organic Matter Effect on Dynamics of P Availability in Upland Ultisol and Lowland Inceptisol

2013 ◽  
Vol 16 (2) ◽  
pp. 107-114
Author(s):  
. Marsi ◽  
. Sabaruddin
Keyword(s):  
Organic Matter ◽  
Fresh Water ◽  
Water Soluble ◽  
Available P ◽  
Phosphate Adsorption ◽  
P Availability ◽  
Soil P ◽  
Soil Available P ◽  
Adsorption Desorption ◽  
Desorption Capacity

Ultisols and Inceptisols were used to investigate the adsorption-desorption capacity of P and the effect of organic matter on the dynamics of P availability in tropical acid soils. The experiment consisted of two sub-experiments. Sub-experiment I was to study the adsorption-desorption capacity of Ultisols, Fresh-water lowland Inceptisols, and tidal-swamp Inceptisols. Therefore, surface soils (0 to 30 cm) of each tested soil were treated with 0, 10, 20, 30, 40, 60, 80, 100, 120, 140, 170, and 200 mg P kg-1 of soil. Sub-experiment II was to study the effects of organic matterapplication (0, 5, 10, and 15 Mg ha-1) on the dynamics of available P following 60d incubation under room temperature.P fertilizer application significantly affected water soluble-P (WSP) (p<0.01) and soil available P-Bray and Kurtz No. 1 (BKP) (p<0.01) in the three tested soils. The different response of both WSP and BKP confirmed that the soils tested in the current experiment had different soil P buffering capacity in the order of Tidal-lowlandInceptisol>Upland Ultisol>fresh-water Lowland Inceptisol. OM application increased the BKP in all tested soils as compared to the control. Differences in pattern of soil available P dynamics over time were detected between upland soil and two lowland soils used in the current experiment.Keywords: Adsorption-desorption, Inceptisols, organic matter, Ultisols

PHOSPHORUS-MOBILIZATION STRATEGY BASED ON CARBOXYLATE EXUDATION IN LUPINS (LUPINUS, FABACEAE): A MECHANISM FACILITATING THE GROWTH AND PHOSPHORUS ACQUISITION OF NEIGHBOURING PLANTS UNDER PHOSPHORUS-LIMITED CONDITIONS

2016 ◽  
Vol 53 (2) ◽  
pp. 308-319 ◽  
Author(s):  
D. M. S. B. DISSANAYAKA ◽  
W. M. K. R. WICKRAMASINGHE ◽  
BUDDHI MARAMBE ◽  
JUN WASAKI
Keyword(s):  
Plant Species ◽  
Lupinus Albus ◽  
Available P ◽  
White Lupin ◽  
P Availability ◽  
Soil P ◽  
Positive Effects ◽  
P Acquisition ◽  
P Pools ◽  
Carboxylate Exudation

SUMMARYThe capability of some plant species to mobilize phosphorus (P) from poorly available soil P fractions can improve P availability for P-inefficient plant species in intercropping. White lupin (Lupinus albus) has been investigated as a model P-mobilizing plant for its capability of enhancing the P acquisition of neighbouring species under P-limited conditions. To date, investigations have led to contrasting findings, where some reports have described a positive effect of intercropped lupins on companion plants, whereas others have revealed no effects. This review summarizes the literature related to lupin–cereal intercropping. It explores the underpinning mechanisms that influence interspecific facilitation of P acquisition. The P-mobilization-based facilitation by lupins to enhance P-acquisition of co-occurring plant species is determined by both available P concentration and P-sorption capacity of soil, and the root intermingling capacity among two plant partners enabling rhizosphere overlapping. In lupin–cereal intercropping, lupin enhances the below-ground concentration of labile P pools through mobilization of P from sparingly available P pools, which is accomplished through carboxylate exudation, where neighbouring species acquire part of the mobilized P. The non-P-mobilizing species benefit only under P-limited conditions when they immediately occupy the maximum soil volume influenced by P-mobilizing lupin. Positive effects of mixed cropping are apparent in alkaline, neutral and acidic soils. However, the facilitation of P acquisition by lupins to companion species is eliminated when soil becomes strongly P-sorbing. In such soils, the limitation of root growth can result in poorer root intermingling between two species. The P mobilized by lupins might not be acquired by neighbouring species because it is bound to P-sorbing compounds. We suggest that the lupins can be best used as P-mobilizing plant species to enhance P acquisition of P-inefficient species under P-limited conditions when plant species are grown with compatible crops and soil types that facilitate sharing of rhizosphere functions among intercropped partners.

Forage biomass yield and arbuscular mycorrhizal symbiosis in a legume and C3 and C4 grasses under increasing soil phosphorus availability

2020 ◽  
Vol 71 (10) ◽  
pp. 907
Author(s):  
Tomás Chippano ◽  
Ileana García ◽  
Noelia Cofré ◽  
Rodolfo Mendoza
Keyword(s):  
Arbuscular Mycorrhizal ◽  
Forage Yield ◽  
Available P ◽  
Shoot Biomass ◽  
P Availability ◽  
Soil P ◽  
Lotus Tenuis ◽  
Soil P Availability ◽  
Wide Range ◽  
Am Symbiosis

Phosphorus (P) is the main limiting factor for forage production in grasslands. It is important to determine levels of available P in soil that optimise production with minimum impact on arbuscular mycorrhizal (AM) symbiosis. We investigated the effects of increasing P availability on biomass production, root morphology, AM symbiosis and P acquisition of a forage legume (Lotus tenuis), a C3 grass (Schedonorus arundinaceus) and a C4 grass (Panicum coloratum) growing on a P-deficient soil in pots with P applied at rates of 0–160 mg kg–1 dry soil. The three forage species responded strongly to addition of P, with 90% of maximum shoot growth reached at available P levels of 24.3 mg kg–1 for L. tenuis, 14.4 mg kg–1 for P. coloratum and 11.2 mg kg–1 for S. arundinaceus. Lotus tenuis and P. coloratum produced higher yields of shoot biomass than S. arundinaceus. Root dry weight was higher in the legume than in the grasses, with the root-mass fraction being lowest in P. coloratum. AM colonisation was higher in L. tenuis roots than in grass roots, and decreased with increased soil P availability, especially in grasses. Low to moderate additions of P did not affect, and could even improve, AM colonisation in L. tenuis roots. For L. tenuis, it is possible to increase forage yield while maintaining high values of AM colonisation at 10–20 mg kg–1 of available P, but for grasses, especially S. arundinaceus, it is difficult to achieve both objectives. The presence of L. tenuis in grasslands or pastures may contribute to maintaining the native AM inoculum under a wide range of soil P availability in regions such as the Salado River basin of Argentina.

Decrease in fungal biodiversity along an available phosphorous gradient in arable Andosol soils in Japan

2013 ◽  
Vol 59 (6) ◽  
pp. 368-373 ◽  
Author(s):  
Zhihua Bao ◽  
Yuko Matsushita ◽  
Sho Morimoto ◽  
Yuko Takada Hoshino ◽  
Chika Suzuki ◽  
...  
Keyword(s):  
Fungal Community ◽  
Fungal Diversity ◽  
Large Scale ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Community Diversity ◽  
Rrna Genes ◽  
Available P ◽  
Available Phosphorus ◽  
P Availability ◽  
Gradient Gel Electrophoresis

Andosols comprise one of the most important soil groups for agricultural activities in Japan because they cover about 46.5% of arable upland fields. In this soil group, available phosphorus (P) is accumulated by application of excessive fertilizer, but little is known about the influence of increasing P availability on microbial community diversity at large scales. We collected soil samples from 9 agro-geographical sites with Andosol soils across an available P gradient (2048.1–59.1 mg P2O5·kg−1) to examine the influence of P availability on the fungal community diversity. We used polymerase chain reaction – denaturing gradient gel electrophoresis to analyze the fungal communities based on 18S rRNA genes. Statistical analyses revealed a high negative correlation between available P and fungal diversity (H′). Fungal diversity across all sites exhibited a significant hump-shaped relationship with available P (R2 = 0.38, P < 0.001). In addition, the composition of the fungal community was strongly correlated with the available P gradient. The ribotype F6, which was positively correlated with available P, was closely related to Mortierella. The results show that both the diversity and the composition of the fungal community were influenced by available P concentrations in Andosols, at a large scale. This represents an important step toward understanding the processes responsible for the maintenance of fungal diversity in Andosolic soils.

Fertilisation phosphatée et potassique dans la culture du pois sec

2010 ◽  
Vol 90 (5) ◽  
pp. 629-636 ◽  
Author(s):  
J. Lafond ◽  
D. Pageau
Keyword(s):  
Pisum Sativum ◽  
Soil Analysis ◽  
Climatic Conditions ◽  
Mineral Fertilizers ◽  
Western Canada ◽  
P Availability ◽  
Grain Yields ◽  
Soil P ◽  
Pisum Sativum L ◽  
Medium Level

In Quebec, the P recommendations for dry peas (Pisum sativum L.) are nearly three times higher than those in western Canada, while recommendations for K are at least 20% lower. The objective of this project was to re-evaluate the P and K needs of dry peas under the climatic conditions of the Saguenay-Lac-Saint-Jean region (Quebec, Canada) in soils with a range of soil P and K availabilities. The treatments consisted of four P rates (0, 20, 40, 80 and 160 kg P2O5 ha–1) and three K rates (0, 50 and 150 kg K2O ha–1). The trials were conducted at two sites over 3 yr. Site 1 was classified as low in P availability and site 2 as medium according to the soil analysis. Both sites had a medium level of soil K availability. Grain yields increased significantly, by 6%, with increasing fertilizer P (3246 to 3437 kg ha–1). Potassium fertilization had no significant effect on grain yields. Grain yields were also 37% higher in the highest soil P site. This low response of the crop to mineral fertilizers was attributed to the significant soil contribution to crop P and K needs. Soil tests have also indicated an enrichment of P and K with large inputs of mineral fertilizers. Thus, a rate of 30-35 kg P2O5 ha–1 for P poor soils would be sufficient to meet the crop needs. For soils with moderate levels of K (201-400 kg K ha–1), a rate of 50 kg K2O ha–1 would be sufficient to meet the crop needs and to maintain the soil fertility. Key words: Enrichment, efficiency, phosphorus, potassium, Pisum sativum L.

scholarly journals Phosphorus Sorption and Lime Requirements of Maize Growing Acid Soils of Kenya

2013 ◽  
Vol 2 (2) ◽  
pp. 116 ◽  
Author(s):  
P. O. Kisinyo ◽  
C. O. Othieno ◽  
S. O. Gudu ◽  
J. R. Okalebo ◽  
P. A. Opala ◽  
...  
Keyword(s):  
Acid Soils ◽  
Base Cations ◽  
Exchange Capacity ◽  
Available P ◽  
Available Phosphorus ◽  
Phosphorus Sorption ◽  
The West ◽  
Soil P ◽  
P Sorption ◽  
East And West

<p>In Kenya, maize (<em>Zea mays</em> L.) is mainly grown on acid soils in high rainfall areas. These soils are known for low available phosphorus (P), partly due to its sorption by aluminium (Al) and iron oxides. The study determined soil P sorption, lime requirements and the effects of lime on soil pH, Al levels and available P on the main maize growing acids soils in the highlands east and west of Rift Valley (RV), Kenya. Burnt lime containing 21% calcium oxide was used. The soils were strongly to extremely acid (pH 4.85-4.07), had high exchangeable Al<sup>3+</sup> (&gt; 2 cmol Al kg<sup>-1</sup>) and Al saturation (&gt; 20% Al), which most maize germplasm grown in Kenya are sensitive to. The base cations, cation exchange capacity and available P (&lt; 10 mg P kg<sup>-1</sup> bicarbonate extractable P) were low, except at one site in the highlands east of RV indicative with history of high fertilizer applications. Highlands east of RV soils had higher P sorption (343-402 mg P kg<sup>-1</sup>) than the west (107-258 mg P kg<sup>-1</sup>), probably because of their high Al<sup>3+ </sup>ions<sup> </sup>and also the energies of bonding between the soil colloids and phosphate ions. Highlands east of RV also had higher lime requirements (11.4-21.9 tons lime ha<sup>-1</sup>) than the west (5.3-9.8 tons lime ha<sup>-1</sup>). Due to differences in soil acidity, Al levels and P sorption capacities within and between highlands east and west of RV, blanket P fertilizer and lime recommendations may not serve all soils equally well.</p>

scholarly journals Species-Specific Root Microbiota Dynamics in Response to Plant-Available Phosphorus

2018 ◽  
Author(s):  
Natacha Bodenhausen ◽  
Vincent Somerville ◽  
Alessandro Desirò ◽  
Jean-Claude Walser ◽  
Lorenzo Borghi ◽  
...  
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Available Phosphorus ◽  
List Type ◽  
P Availability ◽  
Core Microbiome ◽  
Soil P ◽  
Bacteria And Fungi ◽  
Species Specific ◽  
Root Microbiota

SummaryPhosphorus (P) is a limiting element for plant growth. Several root microbes, including arbuscular mycorrhizal fungi (AMF), have the capacity to improve plant nutrition and their abundance is known to depend on P fertility. However, how complex root-associated bacterial and fungal communities respond to changes in P availability remains ill-defined.We manipulated the availability of soil P in pots and compared the root microbiota of non-mycorrhizal Arabidopsis with mycorrhizal Petunia plants. Root bacteria and fungi were profiled using ribosomal operon gene fragment sequencing, we searched for P sensitive microbes and tested whether a P sensitive core microbiome could be identified.Root microbiota composition varied substantially by P availability. A P sensitive core microbiome was not identified as different bacterial and fungal groups responded to low-P conditions in Arabidopsis and Petunia. P sensitive microbes included Mortierellomycotina in Arabidopsis, while these were AMF and their symbiotic endobacteria in Petunia. Of note, their P-dependent root colonization was reliably quantified by sequencing.The species-specific root microbiota dynamics suggest that Arabidopsis and Petunia evolved different microbial associations under the selection pressure of low P availability. This implies that the development of microbial products that improve P availability requires the consideration of host-species specificity.

scholarly journals POSISI CONTOH DAUN UNTUK ANALISIS STATUS FOSFOR (P) PADA BIBIT JARAK PAGAR (Jatropha curcas L.) DAN KADAR P TERSEDIA PADA DAERAH PERAKARANNYA

2020 ◽  
Vol 14 (4) ◽  
pp. 125
Author(s):  
A ARIVIN RIVAIE ◽  
ELNA KARMAWATI ◽  
RUSLI RUSLI
Keyword(s):  
Jatropha Curcas ◽  
Bulk Soil ◽  
Available P ◽  
P Availability ◽  
Leaf Position ◽  
Physic Nut ◽  
Soil P ◽  
Jatropha Curcas L ◽  
Leaf P ◽  
Bray 1

<p>ABSTRAK<br />Status P pada tanaman dapat diduga dengan menganalisis kadar P<br />pada daun, karena daun merupakan suatu bagian tanaman yang sangat<br />aktif. Untuk itu, diperlukan informasi posisi daun yang sesuai untuk<br />dijadikan contoh daun untuk analisis status P tanaman. Percobaan ini<br />bertujuan untuk menentukan posisi daun yang sesuai untuk analisis status<br />P dan mempelajari perbedaan antara kadar P tersedia di tanah dan di<br />rhizosphere, serta hubungannya dengan kadar P daun bibit jarak pagar.<br />Percobaan dilakukan di rumah kaca Balai Penelitian Tanaman Rempah<br />dan Aneka Tanaman Industri (Balittri) Pakuwon, Sukabumi, Jawa Barat,<br />pada September 2006 sampai dengan Juli 2007, disusun dalam rancangan<br />acak lengkap (RAL) dengan 3 (tiga) ulangan. Setiap unit percobaan terdiri<br />atas 20 tanaman. Perlakuan yang diuji adalah: (a) daun ke-1 atau daun<br />yang terletak tepat di bawah kuncup daun yang belum mekar sempurna,<br />(b) daun ke-2 atau daun yang terletak setelah/di bawah daun ke-1, (c) daun<br />ke-3, dan (d) daun ke-4. Parameter yang diamati adalah kadar P daun (%),<br />kadar P tersedia di tanah dan rhizosphere yang diukur dengan metode<br />Bray-1 P. Hasil penelitian menunjukkan bahwa daun ke-2 adalah posisi<br />daun yang sesuai sebagai contoh daun untuk analisis status P pada bibit<br />jarak pagar (Jatropha curcas L.). Kadar P di rhizosphere lebih rendah<br />daripada kadar P di tanah (Bray-1P) yang jauh dari akar jarak pagar. Pada<br />daun ke-2, keeratan hubungan yang ditunjukkan oleh koefisien regresi (R2)<br />antara kadar Bray-1 P di rhizosphere dan kadar P daun jarak pagar (R2 =<br />0.394) lebih tinggi daripada hubungan antara kadar Bray-1 P di tanah dan<br />kadar P daun (R2 = 0.371), sehingga untuk keperluan menggambarkan<br />ketersediaan P tanah atau untuk melihat hubungan P tanah tersedia dengan<br />kadar ataupun serapan P tanaman jarak pagar, akan lebih tepat bila contoh<br />tanah yang diambil berasal dari rhizosphere akar tanaman.<br />Kata kunci: Jarak pagar (Jatropha curcas L.), posisi daun, status P, P<br />tanah tersedia</p><p>ABSTRACT<br />Determination of leaf sample position for analysis of P<br />status in physic nut (Jatropha curcas L.) seedlings and<br />the available P in the root zone<br />Status of P in plants can be quantified by analyzing concentrations<br />of the nutrient in leaf as the leaf is the most active plant part. For this,<br />information on appropriate leaf position as samples for analysis of P status<br />in the plants is needed. A research was conducted with aims to determine<br />an appropriate leaf position of physic nut seedlings and to study<br />differences between the concentrations of available P (Bray-1 P) in the<br />bulk soil and the rhizosphere, along with their relationships with the<br />concentrations of leaf P. The experiment was carried out in a glasshouse of<br />Indonesian Spices and Other Industrial Crops Research Institute,<br />Sukabumi, West Java, from September 2006 to July 2007. The experiment<br />was arranged in a completely randomized design with three replications.<br />Each experimental unit consisted of 20 plants. The treatments were: (a) 1st<br />leaf or a leaf located exactly below the shoot, (b) 2nd leaf or a leaf located<br />below the 1st leaf, (c) 3rd leaf, and (d) 4th leaf. All the leaves were taken<br />from the primary branch of the plants. Parameters measured were P<br />concentrations in the leaf, P concentrations in the bulk soil and the<br />rhizosphere (Bray-1 P). The results showed that the 2nd leaf position was<br />the appropriate leaf position to be taken as samples for the leaf analysis of<br />P status in physic nut (Jatropha curcas L.) seedlings. The concentrations<br />of Bray-1 P in the rhizosphere were lower than that in the bulk soil, which<br />is further away from the roots. The R2 values for the relationships between<br />the Bray-1 P concentrations in the rhizosphere and the the 2nd leaf P<br />concentrations were higher than that between the Bray-1 P concentrations<br />in the bulk soil and the 2nd leaf P concentrations, hence, for the objectives<br />to show the soil P availability or to show the relationships between the<br />available soil P and the concentrations or the P uptake by the physic nut, it<br />will be more accurate if the soil samples are taken from the rhizosphere.<br />Key words: Physic nut (Jatropha curcas L.), leaf position, P status,<br />available soil P</p>

Sign in / Sign up

Export Citation Format

Share Document