Scielo RSS <![CDATA[Journal of soil science and plant nutrition]]> http://www.scielo.cl/rss.php?pid=0718-951620120002&lang=es vol. 12 num. 2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>Water management for wheat grown in sandy soil under climate change conditions</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200001&lng=es&nrm=iso&tlng=es The effect of fertigation regimes on wheat grown in sandy soil was tested in two field experiments in Egypt. The aim of the study was to determine the vulnerability of wheat to extreme weather event under climate change scenarios. Eight fertigation treatments, in addition to farmer irrigation were tested. Two climate change scenarios obtained from Hadley climate change model were incorporated in CropSyst model to assess wheat yield responses to fertigation regimes under these scenarios. The results showed that the highest yield and the highest water use efficiency (WUE) was obtained under irrigation application using 1.2 and 0.8 of Etc, respectively, with fertigation application in 80% of application time in both growing seasons. The calibration of CropSyst model confirmed that the model is able to mimic the growth of wheat and predicted grain, biological yield, and WUE with high degree of accuracy. The highest yield reduction and the lowest WUE under the tested climate change scenarios were obtained from farmer irrigation. It can be concluded that irrigating wheat grown in sandy soil with an amount of either 1.0 or 0.8 of ETc with fertigation application in 80% of application time is recommended to enhance growth and yield, and to reduce wheat's damage caused by extreme climate change. <![CDATA[<b>Influences of organic manure addition on the maturity and quality of pineapple fruits ripened in winter</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200002&lng=es&nrm=iso&tlng=es A field experiment was conducted to investigate the influence of the addition of organic manure on the maturity stage and quality of pineapple fruits ripened in winter. Fertilization was performed with 200 mL peanut-press pulp liquid fertilizer + 20 g compound fertilizer per plant (T1) or 100 mL peanut press pulp liquid fertilizer + 20 g compound fertilizer per plant (T2). Fertilization with 20 g compound fertilizer per plant (T0) was used as the control. The results indicated that organic fertilizer addition promoted maturity. The weight per fruit was increased, and the contents of TSS and total sugars were enhanced, whereas the titratable acid contents were decreased. A sensory evaluation indicated that, after the addition of organic manure, the pineapple fruits were sweeter and more fragrant. More types of ester aroma components having a higher total relative content were identified in T1, and more types of alkenes having a higher total relative content were identified in T2. The relative contents of propanoic acid, 3-(methylthio)-, and methyl ester were increased by organic manure treatments, with the highest being noted in T1 (5.79%), followed by T2 (5.59%), and the lowest was documented in T0 (4.36%). <![CDATA[<b>Alleviation of temperature stress by nutrient management in crop plants</b>: <b>a review</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200003&lng=es&nrm=iso&tlng=es The effect of fertigation regimes on wheat grown in sandy soil was tested in two field experiments in Egypt. The aim of the study was to determine the vulnerability of wheat to extreme weather event under climate change scenarios. Eight fertigation treatments, in addition to farmer irrigation were tested. Two climate change scenarios obtained from Hadley climate change model were incorporated in CropSyst model to assess wheat yield responses to fertigation regimes under these scenarios. The results showed that the highest yield and the highest water use efficiency (WUE) was obtained under irrigation application using 1.2 and 0.8 of Etc, respectively, with fertigation application in 80% of application time in both growing seasons. The calibration of CropSyst model confirmed that the model is able to mimic the growth of wheat and predicted grain, biological yield, and WUE with high degree of accuracy. The highest yield reduction and the lowest WUE under the tested climate change scenarios were obtained from farmer irrigation. It can be concluded that irrigating wheat grown in sandy soil with an amount of either 1.0 or 0.8 of ETc with fertigation application in 80% of application time is recommended to enhance growth and yield, and to reduce wheat's damage caused by extreme climate change. <![CDATA[<b>Biocontrol features in an indigenous bacterial strain isolated from agricultural soil of Gujarat, India</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200004&lng=es&nrm=iso&tlng=es The present investigation was carried out to test the biocontrol potential of a phosphate solubilizing bacterial strain, LK11 isolated from mungbean rhizosphere, in Gujarat, India. This strain besides solubilizing the insoluble P also demonstrated inhibition of Sclerotium rolfsii growth in agar plate and produced a volatile compound, HCN. During in vitro studies LK11 inhibited sclerotia germination by 40%. The most important contributing factor towards increased mungbean growth by reducing fungal attack was the enhanced production of antifungal compounds like PAL (47 mM/ml/mg of tissue), phenolics (90.2 μg/ml/mg) and flavonoids (184.2 mg/ml/g) which is comparable to earlier reports available. Testing the efficiency of this strain in consortium culture alongwith some other PGPR strains and biocontrol microbes at multilocational fields is in offing. <![CDATA[<b>Effect of integrated use of cattle manure and inorganic fertilizers on tuber yield of potato in Ethiopia</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200005&lng=es&nrm=iso&tlng=es A field experiment was conducted to assess the effect of farmyard (cattle) manure (FYM) and inorganic nitrogen (N) phosphorus (P) fertilizers on growth and tuber yield of potato (Solanum tuberosum L.). The treatments consisted of factorial combination of 4 levels of FYM (0. 10, 20 and 30 t h-1) and three levels of inorganic NP fertilizers (0, 33.3%, 66.6% recommended rates) laid out in a Randomized Complete Block Design (RCBD) replicated three times. Results demonstrated that the application of 20 or 30 t ha-1 FYM + 66.6% of the recommended inorganic NP fertilizers significantly increased total tuber yield over the application of full dose of inorganic NP fertilizers without FYM in vertisol whereas in nitosol, the highest level of FYM (30 t ha-1) + 66.6% of the recommended inorganic NP fertilizers significantly improved total tuber yield over the application of full dose of inorganic NP fertilizers without FYM. The application of 10 t ha-1 FYM + 66.6% of the recommended inorganic NP fertilizers and 20 or 30 t ha-1 FYM + 33.3% of the recommended inorganic NP fertilizers gave a total tuber yield, which was on par with the tuber yield obtained due to the application of full dose of inorganic NP fertilizer alone, in both soils. Thus, the application of 10 t ha-1 and 20 or 30 t ha-1 FYM resulted in a saving of 33.3% and 66.6% of the recommended NP fertilizers, respectively without significantly reducing the total tuber. <![CDATA[<b>The reduction in proline buildup in mycorrhizal plants affected by nematodes</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200006&lng=es&nrm=iso&tlng=es Plants stressed by pathogens activate a variety of defense mechanisms to survive. The osmoprotector amino acids, including proline, are among these defense mechanisms. In this work, the effects of arbuscular mycorrhizal fungi on plants infested by root-knot nematodes were evaluated with regard to the accumulation of the osmoprotectant proline. A 2x3 factorial design was established with 8 treatments -with and without nematodes, with and without mycorrhizae, and with and without fertilizer application - with 4 replicates. Two weeks after inoculation with arbuscular mycorrhizal fungi, the plants were infested with 4 nematode egg masses, and 8 weeks later, the plants were harvested. The inoculation with the arbuscular mycorrhizal fungi significantly reduced the proline content, with the non-inoculated plants exhibiting a higher concentration. Neither the infestation of the nematodes nor the addition of fertilizer significantly affected the proline content. Plant height, stem diameter, leaf area, number of leaves, and fresh weight were significantly improved by the presence of the arbuscular mycorrhizal fungi. The interaction of the fungi and the fertilizer did have a significant effect for height and leaf area. The nematode infestation and the fertilization did not affect mycorrhizal colonization. <![CDATA[<b>Crop residue grazing and tillage systems effects on soil physical properties and corn (Zea <i>mays</i> L.) performance</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200007&lng=es&nrm=iso&tlng=es Abstract Crop-livestock systems under no till (NT) could negatively affect soil physical properties and crop performance, due to the additive effects of reduced soil cover and cattle trampling due to livestock grazing, and the absence of tillage. We evaluated the effects of four grazing strategies and of a shallow tillage (ST) on soil physical properties and corn (Zea mays L.) performance for a mollisol after 15 years under crop-livestock systems under NT in Argentina. Grazing strategies evaluated were: closure (C), one grazing (OG), high stocking rate (HR) and farmer's management (FM), and the tillage systems were: NT and ST. Bulk density (BD), penetration resistance (PR), hydraulic conductivity (k s), plant population, surface root distribution, aboveground dry matter accumulation, aboveground total N (TN) accumulation and corn yield were evaluated. High stocking rate and FM increased RP. On the other hand, ST decreased PR and BD and increased k s Corn yield was higher under ST than under NT, and under HR than under the other grazing strategies. Total N accumulation was higher under HR than under the rest of grazing strategies. Rational grazing management and use of tillage systems on resilient soils could have prevented soil physical properties be affected beyond critical thresholds. <![CDATA[<b>Effects of the co-inoculation with saprobe and mycorrhizal fungi on <i>Vaccinium corymbosum</i> growth and some soil enzymatic activities</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200008&lng=es&nrm=iso&tlng=es In this study we evaluated the initial plant growth and some biochemical changes produced in rizhosphere soil of blueberry (Vaccinium corymbosum L.) cv. 'Elliot' plantlets obtained from in vitro culture and inoculated with six arbuscular mycorrhizal (AM) fungi strains (Gigaspora rosea; Glomus claroideum; G. deserticola; G. viscosum; G. intraradices and G. constrictum) and five saprobe fungi (Coriolopsis rigida; Phanerochaete chrysosporium; Trametes versicolor; Trichoderma harzianum and Penicillium chrysogenum). Our results showed a significant "like" AM root colonization (25-46%), highlighting the treatment co-inoculated with G. rosea + P chrysosporium or C. rigida; G. intraradices + C. rigida; G. viscosum + P chrysosporium, but this root colonization was morphologically atypical, and dominated by interstitial hyphae, without develop of other typical AM structures. Furthermore, significant increase in the shoot and root growth of the plantlets inoculated with G. viscosum + P chrysosporium, and G. intraradices + C. rigida were observed. On the other hand, G. claroideum + T. versicolor showed the high increase in the dehydrogenase enzyme activity, while inoculation with G. claroideum alone showed the greatest β-glucosidase activity. These results suggest that the interaction of AM symbionts together with saprobe fungi could be a biological alternative to promote the growth of micro-propagated blueberry plantlets in their early growth stages. <![CDATA[<b>Simple linear algorithm to estimate the space-time variability of precipitable water in the Araucanía Region, Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200009&lng=es&nrm=iso&tlng=es This work proposes a linear algorithm which relates precipitable water (PW) with altitude and distance from the coast, on a regional scale. For precipitable water, the ERA-Interim (ECMWF) database for the period 1989-2010 was used, while a digital elevation model was used for the geographical variables. The results obtained indicate statistical significance between the two variables (p< 0.01), with a confidence level of 99%. The model makes it possible to describe the mean monthly space-time variability of precipitable water, stratifying the study area into clearly differentiated zones. <![CDATA[<b>Suppressive effect of olive residue and saprophytic fungi on the growth of <i>Verticillium dahliae</i> and its effect on the dry weight of tomato <i>(Solanum lycopersicum</i> L.)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200010&lng=es&nrm=iso&tlng=es The saprophytic fungi Aspergillus niger, Coriolopsis rigida, Fusarium lateritium, F. oxysporum, Mucor racemosus, Paecilomyces farinosus, Penicillium chrysogenum, P. restrictum, Trametes versicolor, Trichoderma harzianum, T. pseudokoningii and T. viride were able to decrease the growth in vitro of Verticillium dahlie in the presence of aqueous extract of olive residue. The conidia number of V. dahliae decreased when grown on aqueous extract of olive residue, autoclaved or filtered through 0.45 micron filters after culture of the fungi. These results suggest not only the predominance of suppressive substances of a biological nature, but also the existence of non-biological inhibitory substances. The olive residue decreased the negative effect of V. dahliae on shoot and root dry weight of tomato (Solanum lycopersicum L.), by the antifungal compounds present in the olive residue and by the antifungal substances produced by the antagonistic saprophytic fungi grown in this residue. <![CDATA[<b>Phytotoxic effect of paper pulp sludge on Alfisol soil</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200011&lng=es&nrm=iso&tlng=es The aim of this study was to evaluate the phytotoxicity of different doses of paper pulp sludge on Alfisol soil in order to determine the potential use of the sludge as a soil improver. The organic waste was physically and chemically characterized to determine the presence of nutrients and heavy metals which is important for plant growth. The germination index (GI), the radicle length and the hypocotyl length of Lactuca sativa L. and Lolium perenne L. were evaluated for six doses of sludge/ soil: 10, 25, 50, 75, 100 and 150 t ha-1. A control without waste addition was also included. Results indicated low concentration of heavy metals in the sludge which is reflected in the non-toxic effect on seed germination. GI in Lactuca sativa L. reached a maximum in the control with 155%; however, there were no significant differences among the treatments. GI in Lolium perenne L. had the highest value at a dose of 50 t ha-1 with 143%, indicating significant differences between the treatments. The use of paper pulp sludge as a soil improver could be beneficial given the nutrient concentration, the low concentration of heavy metals and the no toxic effect depending on the species treated. <![CDATA[<b>Antifungal activity of wheat root exudate extracts on <i>Gaeumannomyces graminis</i> var. <i>Tritici</i> growth</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200012&lng=es&nrm=iso&tlng=es Wheat (Triticum aestivum L.) is known for its ability to produce and release al-lelopathic compounds, which have potential for controlling weeds and diseases. Previous reports have shown the fungitoxic effects of allelochemicals present in wheat. Thus, these compounds can be exuded by roots to protect the tissues directly affected by Gaeumannomyces graminis var. tritici (Ggt) fungus that causes wheat take-all disease. The aim of this research was to evaluate in vitro the allelopathic effect of root exudate extracts from four Chilean wheat cultivars on Ggt growth. Root exudates were released from wheat seedlings to a sterile culture medium without nutrients. Afterward, the exudates in the culture medium were separated by liquid-liquid extraction using ethyl acetate. Eight different concentrations were tested for each cultivar. The results showed that the degree to which the extracts strongly inhibit the phytopathogen growth is highly dependent on both the concentration and the cultivar. The root extract of the Domo cultivar was significantly active against Ggt (MIC=0.36 mg mL-1). IC50 and MIC values obtained for Dollinco and Domo root exudate extracts showed toxicity to Ggt. These findings may be considered in future studies related to the use of allelopathic potential as a selection factor in order to reduce the yield losses caused by various take-all diseases, as an alternative to chemical controls. <![CDATA[<b>Using a chlorophyll meter to estimate tea leaf chlorophyll and nitrogen contents</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200013&lng=es&nrm=iso&tlng=es A chlorophyll meter can conveniently estimate foliar chlorophyll and nitrogen (N) contents in many species. The objective of this study was to evaluate the utility of a chlorophyll meter to inform nitrogen fertilization rates of tea (Camellia sinensis L.) at different places and times. Plot-scale (5 x 20 m) experiments with three replications were conducted in 2010. Each plot was treated with 248 kg pure N ha-1 per year as urea. At the same time, a field-scale (32 ha) experiment, with the same fertilization rate, was conducted at the same plantation. Tea leaves were sampled in August and November and analyzed with a chlorophyll meter in situ and in the lab. The chlorophyll and nitrogen contents and chlorophyll meter (SPAD) readings of tea leaves in August were greater than in November, and plot-scale values were greater than field-scale values. SPAD readings could estimate the chlorophyll content of tea leaves regardless of temporal and spatial considerations. However, space and time must be considered when using SPAD readings to estimate the nitrogen content of tea leaves. <![CDATA[<b>Effects of phosphorus and organic fertilizers on phosphorus fractions in submerged soil</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200014&lng=es&nrm=iso&tlng=es This study was conducted in order to evaluate effects of phosphorous fertilizer (PF)s from sources of triple superphosphate (TSP) and di-ammonium phosphate (DAP) and organic fertilizer (OF)s from sources of cow dung manure (CDM) and municipal solid waste compost (MSWC) on phosphorous (P) fractions include aluminium-P (Al-P), iron-P (Fe-P), Reductant soluble-P (RS-P), calcium-P (Ca-P) and avail-able-P (Olsen-P) fractions under rice cultivation condition. The trials were carried out in calcareous and acidic soils. PFs were added at three levels (10, 20 and 30 mg kg-1) and OFs was applied at the rate of 10 t.ha-1. Results of this study showed that Ca-P was the predominant form of P in calcareous soil while Fe-P and Al-P were predominate in acidic soils. In calcareous soil, all forms of P under submerged conditions had been increased because of using PFs both alone and in combination with OFs. In acidic soil, significant amounts of P fractions were found only in Fe-P and RS-P fractions. Accordingly, Fe-P fraction increased in 10 mg kg-1 treatment and RS-P increased in MSWC treatment. Among the inorganic P fractions in calcareous soil, only RS-P; and in acidic soil, Ca-P and Fe-P significantly correlated to Olsen-P. <![CDATA[<b>The aggregates stability indicator <ASItest> to evaluate soil spatiotemporal change in a tropical dry ecosystem</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162012000200015&lng=es&nrm=iso&tlng=es In this work, aggregate stability was evaluated as a quality indicator in soils of tropical dry deciduous forests (TDF) with relation to land use, the sampling position in the hillslope and the sampling season. The study was done on a representative morpho-edaphological unit of the tropical dry ecosystems (hillslope on granite with eutric regosol) on the coast of the state of Jalisco, Mexico. The evaluated soil aggregation indexes were: Aggregate stability index (ASI)test, maximum stability, minimum stability, relative index of variability, and the index of quality of aggregation change. These indexes showed differences in soil aggregation resulting from changes in land use (conserved TDF, grazed TDF, and cultivated pasture). The indexes showed that there is greater stability of the aggregates during the rainy season than in the dry season; as well as in the higher part of the slope than in the lower one. The relationship of the edaphic properties with the ASItest indicator was mainly with radical volume, and less so with exchangeable bases (calcium and magnesium), clay, and organic carbon. The proposed soil aggregation indexes allowed monitoring spatiotemporal changes in soil structure.