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Made available in DSpace on 2022-04-29T08:36:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Techniques to increase grain production such as nitrogen fertilization and plant growth regulators are essential to enable and enhance rice yield. Therefore, our goal was to evaluate the effect of nitrogen fertilization and application of trinexapac-ethyl on vegetative and reproductive traits of upland rice. Experiments were established in Registro, Brasil during the 2011 and 2014 growing seasons and treatments tested consisted of N rates (0; 50; 100; 150; and 200 kg N ha−1) and timings of TE application: V4, V7, R1 and control (without TE). Upland rice grain yield at N rates greater than 117 kg ha−1 applied as topdress combined with TE application at V7 will start to decrease grain yield. In addition, application of TE at V7 combined with N rates equal to or close to 117 kg ha−1 will lead to higher yields and shorter plants. The combination of N application at topdress combined with TE application at V4 led to a linear increase in the number of grains per panicle of rice plants. Nitrogen topdressing was found to increase plant height in the absence to TE or when TE is sprayed at V4 or R1. In addition, nitrogen topdressing had a positive increase in the number of tillers, stems, panicles, and SPAD index in rice plants. College of Agricultural and Technological Sciences São Paulo State University (Unesp), Dracena. Rod. Cmte João Ribeiro de Barros, km 651 - Bairro das Antas, Dracena São Paulo State University (Unesp) Campus of Registro, SP Tropical Root and Starches Center São Paulo State University (Unesp), SP College of Agriculture and Veterinary Sciences São Paulo State University (Unesp), SP Department of Soil Water and Climate Southwest Research and Outreach Center University of Minnesota, 23669, 130th, St. College of Agricultural and Technological Sciences São Paulo State University (Unesp), Dracena. Rod. Cmte João Ribeiro de Barros, km 651 - Bairro das Antas, Dracena São Paulo State University (Unesp) Campus of Registro, SP Tropical Root and Starches Center São Paulo State University (Unesp), SP College of Agriculture and Veterinary Sciences São Paulo State University (Unesp), SP

Made available in DSpace on 2022-05-01T08:44:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The interactive effectof silicon (Si) application on soil fertility is poorly understood when inoculation with Azospirillum brasilense is performed. This research determined if Si application and A. brasilense inoculation to corn (Zea mays L.) and wheat (Triticum aestivum L.) has agronomic benefits on soil nutrient concentration and grain yield. Treatments were tested under a no-till system in a Rhodic Haplustox in a full factorial design with four replicates and comprised (a) two soil amendment sources—calcium (Ca) and magnesium (Mg) silicate and dolomitic limestone; (b) with and without seed inoculation with A. brasilense; and (c) five sampling dates collected during two corn–wheat crop rotations (2015–2017). Calcium and Mg silicate application was effective at decreasing soil hydrogen + aluminum (H+Al) and Al content and increasing soil pH, sum of bases, and base saturation. However, silicate changed soil nutrient availability, reduced cation exchange capacity, phosphorus (P) and Mg content and did not significantly affect (p >.05) corn and wheat grain yield. Inoculation reduced Al toxicity, with lower H+Al and Al contents, and increased K content, leading to a greater pH and base saturation after four cropping seasons. Inoculation increased corn and wheat grain yield by 8.2 and 8.3%, respectively. Application of Ca and Mg silicate was more effective than limestone as a liming agent but could result in decreased availability of certain nutrients in soil. Inoculation with A. brasilense could be an important management practice to maintain adequate Si content in soil when limestone is applied. However, with silicate application, A. brasilense could increase Si depletion in soil. Center for Nuclear Energy in Agriculture Univ. of São Paulo Dep. of Soil Water and Climate Univ. of Minnesota Southwest Research and Outreach Center Dep. of Plant Health Rural Engineering and Soils São Paulo State Univ. Dep. of Plant Health Rural Engineering and Soils São Paulo State Univ.

Made available in DSpace on 2022-05-01T09:30:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This study was developed to investigate if Ca and Mg silicate application as Si source combined with inoculation with Azospirillum brasilense and N rates can affect corn nutrient uptake. The study was set up in a Rhodic Hapludox under no-till system, located in Selvíria, state of Mato Grosso do Sul, Brazil. Treatments included: (i) two seed inoculation (with and without A. brasilense); (ii) two soil amendment sources (Ca and Mg silicate as Si source and dolomitic limestone); and (iii) five N application rates applied as side-dress (0 to 200 kg ha−1). Increasing N rates positively influenced corn nutrition with increased nutrient and Si uptake in shoot and grain. The average nutrient uptake in descending order was K > N > Ca > Si > Mg > S > P >Fe > Mn > Zn > Cu > B for shoot and N > K > P > S > Mg > Ca > Si> Fe > Zn > Mn > B > Cu for grain. Calcium and Mg silicate application positively influenced corn nutrition with greater shoot P, K, Ca, S, and B uptake and grain Ca uptake. Inoculation with A. brasilense was found to increase nutrient uptake with greater shoot N, K, Ca, B, and Si and grain Cu uptake. Grain N and S increased by 22.5 and 26.8% when plants were inoculated and 200 kg N ha−1 was applied and grain Zn increased by 88.6, 65.7, and 99% when plants were inoculated and 50, 150, and 200 kg N ha−1 were applied, respectively. Therefore, studies conducted under tropical conditions are needed to better understand the role of Si combined with PGPB inoculation under different N management and their effects on plant nutrition and cereal development aiming at improving nutrient replenishment. Department of Plant Health Rural Engineering and Soils São Paulo State University Department of Soil Water and Climate University of Minnesota Southwest Research and Outreach Center Department of Plant Health Rural Engineering and Soils São Paulo State University

Made available in DSpace on 2021-06-25T10:21:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-04-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Stable isotopes (e.g., 15N) can be used to develop best practices for fertilizer management in cereal crops under tropical conditions. The objectives of this study were to determine the N contribution from fertilizer and soil to wheat and corn grown in rotation and the residual N contribution from fertilizer applied to wheat and carried over to corn under Brazilian savannah conditions. This study was established in a no-till system on Rhodic Haplustox soil in a randomized complete block design with four replications. The N treatments applied to the wheat crops were 0, 20, 40, 60, 80 and 160 kg (urea-15N) ha−1. The residual effects of N on the succeeding corn crop were evaluated. During the corn phase, two additional treatments were included: a control (0 N) and a treatment with 160 kg N ha−1. Regression analysis showed that the highest estimated wheat yield (5415 kg ha−1) was observed with the application of 114 kg N ha−1. Significant effects from the residual N were observed in the corn shoot biomass and straw N uptake. On average, the recovery rate of the urea N fertilizer was 34% for wheat, and the residual urea N fertilizer use in corn (when applied to wheat) was less than 5% of the amount initially applied. The effect of the residual N was not enough to meet the N demands of the succeeding corn crop. The results of this study provide producers and the scientific community with good estimates of nitrogen use efficiency for wheat and corn. Department of Plant Health Rural Engineering and Soils College of Engineering Sao Paulo State University (UNESP), Avenida Brasil, 56 - Centro Goiano Federal Institute, Rio Verde Campus Department of Soil Water and Climate Southwest Research and Outreach Center University of Minnesota Center for Nuclear Energy in Agriculture University of Sao Paulo Department of Plant Health Rural Engineering and Soils College of Engineering Sao Paulo State University (UNESP), Avenida Brasil, 56 - Centro FAPESP: 18/08485-7 CNPq: 312359/2017-9

Corn stover is a global resource used in many industrial sectors including bioenergy, fuel, and livestock operations. However, stover removal can negatively impact soil nutrient availability, especially nitrogen (N) and phosphorus (P), biological activity, and soil health. We evaluated the effects of corn stover management combined with N and P fertilization on soil quality, using soil chemical (nitrate, ammonium and Bray-1 P) and biological parameters (β-glucosidase, alkaline phosphatase, arylsulfatase activities and fluorescein diacetate hydrolysis—FDA). The experiment was performed on a Mollisol (Typic Endoaquoll) in a continuous corn system from 2013 to 2015 in Minnesota, USA. The treatments tested included six N rates (0 to 200 kg N ha−1), five P rates (0 to 100 kg P2O5 ha−1), and two residue management strategies (residue removed or incorporated) totalling 60 treatments. Corn stover management significantly impacted soil mineral-N forms and enzyme activity. In general, plots where residue was incorporated were found to have high NH4+ and enzyme activity compared to plots where residue was removed. In contrast, fields where residue was removed showed higher NO3− than plots where residue was incorporated. Residue management had little effect on soil available P. Soil enzyme activity was affected by both nutrient and residue management. In most cases, activity of the enzymes measured in plots where residue was removed frequently showed a positive response to added N and P. In contrast, soil enzyme responses to applied N and P in plots where residue was incorporated were less evident. Soil available nutrients tended to decrease in plots where residue was removed compared with plots where residue was incorporated. In conclusion, stover removal was found to have significant potential to change soil chemical and biological properties and caution should be taken when significant amounts of stover are removed from continuous corn fields. The residue removal could decrease different enzymes related to C-cycle (β-glucosidase) and soil microbial activity (FDA) over continuous cropping seasons, impairing soil health.

One of the steps needed to achieve sustainable bioenergy is to reduce our reliance on synthetic nitrogen (N). Despite the fact that legume cover crops have the potential to increase soil quality and sugarcane (Saccharum spp.) yield, much information is still needed to determine amount of N available from cover crops to sequential ratoon cycles. This study was designed to assess the impacts of sunn hemp (Crotalaria spectabilis) cover crop on soil N dynamics and sugarcane ratoon response to N fertilization during two harvest seasons across three contrasting soil and climatic conditions in southern Brazil. The treatments consisted of cover crop and fallow established prior to sugarcane replanting; in addition to three N-fertilizer rates 60, 120 and 180 kg N ha−1 and a 0-N control applied during the first and second ratoons. Although there was increased sugarcane yield (8–13 Mg ha−1 in first ratoon and 10–16 Mg ha−1 in second ratoon) in plots planted with cover crop, it was not possible to detect significant increases in soil inorganic N, microbial biomass C and Illinois Soil N Test content under cover crop compared with fallow. Cover crop with sunn hemp increased the accumulated two-year yields by 14–25 Mg ha−1 at all sites and NUE (Mg stalks kg−1 N) across all N rates at two sites. Our findings support the conclusion that cover crop did not change the N requirement of succeeding ratoon crops but increases the yield, thereby improving NUE in sugarcane systems.

Made available in DSpace on 2021-06-25T10:11:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) A better understanding of nitrogen (N) behavior and agronomic practices is needed to improve biological nitrogen fixation (BNF) and N use efficiency under field conditions. This study aims on investigating the potential for the use of biological agents that can fix atmospheric N and are related to multiple mechanisms benefits to improve cowpea (Vigna unguiculata (L.) Walp.) development and productivity, leading to a positive residual effect on wheat (Triticum aestivum L.) development. The study was set up under a no-till system in a Rhodic Haplustox, in a randomized complete block design, with four replicates. Treatments were tested in a full factorial design and included: i) three types of inoculation (without inoculation – control; Bradyrhizobium sp. inoculation (strains SEMIA 6462 and SEMIA 6463) – the conventional inoculation of cowpea; and Bradyrhizobium sp. combined with A. brasilense (strains Ab-V5 and Ab-V6) – the co-inoculation); and ii) five N rates (0 to 160 kg N ha−1) applied as urea-15N isotope. The residual effects of inoculations and N application rates applied during the cowpea growing season were evaluated on wheat (successor crop). Co-inoculation was found to increase cowpea grain yield by 40.5% and 14.1% compared to the control and Bradyrhizobium sp. inoculation when N was omitted and up to 37.6% and 50.8% when N was applied. Co-inoculation increased N use efficiency, N recovery and N accumulation on cowpea, leading to improved crop growth. The co-inoculation also provided a positive residual effect on wheat resulting in increased plant N accumulation, crop development, and greater wheat grain yield compared to the control (increase of 7.8%) and Bradyrhizobium sp. inoculated plants (increase of 5.8%). Co-inoculation was found to increase N use efficiency on cowpea by 216.5% and 35.5% and on wheat by 159.3% and 29.5% compared to control and Bradyrhizobium sp. inoculation, respectively. The fertilizer N recovery was, on average, 22.2% by cowpea, while fertilizer N recovery by wheat was

Made available in DSpace on 2020-12-10T20:06:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-07-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) New management practices are needed to help improve the inoculation efficiency of plant growth-promoting bacteria (PGPB). The use of silicon (Si) combined with PGPB can be a useful and sustainable strategy to enhance cereal development under tropical conditions. This research was developed to investigate inoculation methods withAzospirillum brasilensecombined with Si application as a soil amendment in corn. The effects of Si application andA. brasilenseinoculation on plant development and yield were tested on corn for two consecutive years. The study was set up in a Rhodic Hapludox under a no-till system in a completely randomized block design with four replicates. Treatments were tested in a full factorial design (triple factorial 4 x 2 x 2) and included (i) 4 inoculation methods (control, seed, in-furrow, and leaf), (ii) two lime sources (calcium and magnesium silicate and dolomitic limestone), and (iii) two study years (2015/2016 and 2016/2017). Our results showed that seed and in-furrow inoculation were more effective in promoting corn development and greater yield, with an increase of 10.6 and 7.3% in corn grain yield, respectively. Silicate application combined with seed inoculation increased shoot N uptake and root biomass. Also, Si application increased leaf chlorophyll index, stem diameter, and had similar effects on soil properties compared with limestone. Our results showed positive effects on corn growth and productivity as a result of inoculation, while the potential benefits of Si use were less evident. Sao Paulo State Univ, Dept Plant Protect Rural Engn & Soils, Ave Brasil 56, BR-15385000 Ilha Solteira, SP, Brazil Rua Moncao 830, BR-15385000 Ilha Solteira, SP, Brazil Univ Minnesota, Southwest Res & Outreach Ctr, Dept Soil Water & Climate, 23669 130th, St Lamberton, MN 23669 USA Sao Paulo State Univ, Dept Plant Protect Rural Engn & Soils, Ave Brasil 56, BR-15385000 Ilha Solteira, SP, Brazil FAPESP: 17/06002-6 CNPq: 312359/2017-9

Alternative grazing systems that incorporate cover crops may be useful to achieve a longer grazing season and maximize forage production. However, little is known about their impact on soil properties, especially in the presence or absence of cattle grazing in the early spring. The aim of this study was to evaluate the interacting effects of cropping systems with and without cattle grazing in rotation with corn or soybean on the balance and dynamics of soil fertility and enzyme activity. This study was conducted as a system experiment between 2015 and 2019 in Minnesota and Pennsylvania, USA. The experimental design was a randomized complete block design with four replications. Treatments included presence or absence of cattle grazing and two types of cropping systems (pasture-rye-soybean-pasture [P-R-SB-P] and pasture-wheat/vetch-corn-pasture [P-W/V-C-P]. Soil samples were collected six times during the study. Soil properties analyzed were soil pH, organic matter, salinity, K, Ca, Mg, cation exchange capacity (CEC), P, &beta, glucosidase, alkaline phosphatase, aryl-sulfatase, fluorescein diacetate hydrolysis, ammonium, nitrate, permanganate oxidizable carbon (POXC), N%, C%, S%, and C:N ratio. Grazing increased glucosidase activity, available Ca, Mg, NO3&minus, NH4+, soil pH, soil C%, S%, and the C:N ratio. In the P-W/V-C-P cropping system, soil pH, available Ca, NO3&minus, and sulfatase activity were found to increase compared with the P-R-SB-P cropping system. In contrast, soil OM, available K, Mg, CEC, glucosidase, phosphatase, POXC, and total C%, N%, and S% were greater in the P-R-SB-P cropping system compared with the P-W/V-C-P cropping system. The results of this study suggested that rotational grazing can increase soil quality and microbial decomposition under the P-W/V-C-P cropping system, and that this result was greater than under the P-R-SB-P cropping system, leading to a faster nutrient cycling. These results show promise for producers who are seeking methods to diversify their farming operation and reduce the need for external inputs.

Made available in DSpace on 2020-12-12T02:38:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-01 This research was developed to investigate the use of Azospirillum brasilense to enhance N use in wheat cropping systems and to assess the potential interactions between inoculation and urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT). The study was set up under a no-till system in a Rhodic Hapludox. The experimental design was a randomized completely block design with four replicates arranged in a two N source (urea with and without NBPT) × five N rate applied as side dress (0–200 kg ha−1) × two inoculation (with and without A. brasilense) factorial scheme. Inoculation with A. brasilense in combination with application of 100 and 150 kg N ha−1 was found to increase grain yield by 19.6 and 18.8%, respectively. Inoculation also increased biomass N uptake by 66.9% when N was omitted. Inoculation and NBPT application were found to increase NUE by 23.7% compared to inoculation in combination with conventional urea and by 140% compared to NBPT without inoculation. In addition, inoculation increased plant height and NUE by 13.2 and 49%, respectively, compared with non-inoculated plots. Conventional urea and urea with NBPT had a similar effect on nutrient concentration, N uptake, leaf chlorophyll index, biomass weight and wheat grain yield. This study showed positive improvements in wheat production parameters as a result of inoculation, but the potential benefits of NBPT use were less evident. Further research should be conducted under growing conditions that provide increased N volatilization to better study the potential of NBPT application. Department of Plant Health Rural Engineering and Soils Sao Paulo State University (UNESP) College of Engineering, Avenida Brasil, 56 - Centro Department of Soil Water and Climate University of Minnesota Southwest Research and Outreach Center, 23669 130th St. Department of Plant Health Rural Engineering and Soils Sao Paulo State University (UNESP) College of Engineering, Avenida Brasil, 56 - Centro

Made available in DSpace on 2020-12-10T20:00:30Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-08 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Alternative management practices are needed to minimize the need for chemical fertilizer use in non-leguminous cropping systems. The use of biological agents that can fix atmospheric N has shown potential to improve nutrient availability in grass crops. This research was developed to investigate if inoculation with Azospirillum brasilense in combination with silicon (Si) can enhance N use efficiency (NUE) in maize. The study was set up in a Rhodic Hapludox under a no-till system, in a completely randomized block design with four replicates. Treatments were tested in a full factorial design and included: i) five side dress N rates (0 to 200 kg ha(-1)); ii) two liming sources (Ca and Mg silicate and dolomitic limestone); and iii) with and without seed inoculation with A. brasilense. Inoculation with A. brasilense was found to increase grain yield by 15% when N was omitted and up to 10% when N was applied. Inoculation also increased N accumulation in plant tissue. Inoculation and limestone application were found to increase leaf chlorophyll index, number of grains per ear, harvest index, and NUE. Inoculation increased harvest index and NUE by 9.5 and 19.3%, respectively, compared with non-inoculated plots. Silicon application increased leaf chlorophyll index and N-leaf concentration. The combination of Si and inoculation provided greater Si-shoot accumulation. This study showed positive improvements in maize growth production parameters as a result of inoculation, but the potential benefits of Si use were less evident. Further research should be conducted under growing conditions that provide some level of biotic or abiotic stress to study the true potential of Si application. Sao Paulo State Univ, Dept Plant Hlth Rural Engn & Soils, Ilha Solteira, SP, Brazil Univ Minnesota, Southwest Res & Outreach Ctr, Dept Soil Water & Climate, Lamberton, MN USA Coll Objet, Higher Educ Inst Rio Verde, Rio Verde, Go, Brazil Sao Paulo State Univ, Dept Plant Hlth Rural Engn & Soils, Ilha Solteira, SP, Brazil FAPESP: 2017/06002-6 CNPq: 312359/2017-9

This research was conducted to investigate the impact of corn cob gasification biochar (CCGB), switchgrass pyrolysis biochar (SPB), turkey manure ash (TMA), and triple superphosphate fertilizer (TSP) on soil phosphorus (P) distribution in three agricultural soils from Minnesota, USA. Understanding how biochar can change soil P distribution is crucial to develop best management practices for recycling biochar products. Phosphorus sources were incorporated at rates of 0, 28, 56, and 84 mg PO kg to 1.5 kg of each soil in 2-L pots. Corn (L.) plants were grown (2 plants pot) in treated soils for 56 d after emergence. After 56 d, plants were harvested and soil samples collected for sequential P fractionation (HO, 0.5 mol L NaHCO, 0.1 mol L NaOH, and 1.0 mol L HCl) and enzymatic hydrolysis. The results of the sequential fractionation showed that CCGB and SPB were as effective as TSP and TMA at increasing total P extractable in water and HCl. In contrast, the increase in NaHCO and NaOH extractable total P was higher with TSP and TMA than with the CCGB and SPB. In most cases, the increase in inorganic P was similar between biochar and TSP, suggesting that biochar could supply equal amounts of plant available P as commercial fertilizer. The effects of biochar on enzymatically hydrolysable P were not consistent and varied by soil. In conclusion, the results of this study showed that biochar has potential to increase the available P pools in soils similar to commercial fertilizer.

Bio-ethanol production from corn stover harvest would change nutrient removal, in particular nitrogen (N) and phosphorus (P), affecting nutrient replenishment and corn development under field-grown conditions. This research was developed to investigate whether stover removal had any influence on the amount of N and P fertilizer required for maximum corn production in the United States (US) Midwest in a stover removal scenario. This study was conducted in Lamberton, MN on a Typic Endoaquoll under continuous corn from 2013 to 2015. The treatments included six N rates (0 to 200 kg N ha−1 in 40 kg increments), five P rates (0 to 100 kg P2O5 ha−1 in 25 kg increments), and two residue management strategies (residue removed or incorporated). Residue management was found to have a significant impact on corn response to N and P application. We verified that residue-removed plots yielded more and therefore required more N and P application from fertilizers. Grain yield after residue was removed was greatest with the highest N and P2O5 rates, whereas grain yield after residue was incorporated was greatest with intermediate N and P2O5 rates in 2013 and 2014. In 2015, residue management did not significantly affect grain yield. Grain N and P accumulation followed a similar behavior as that observed for grain yield. In general, residue removal decreased nutrient availability, while in the residue-incorporated treatment, those nutrients were returned. Although the results of the study showed potential for biomass harvest, it also indicated that nitrogen immobilization and nutrient depletion from the soil could be a limiting factor.

Timing and rate of nitrogen (N) fertilizer application can influence maize (Zea mays L.) grain yield, N uptake, and nitrogen use efficiency (NUE) parameters, but results have been inconsistent across the upper Midwest. This study compared single (fall and preplant) and split applications of differing N rates for maize under irrigated conditions on loamy sand at Becker, MN and under rainfed conditions on loam and clay loam soils at Lamberton, MN and Waseca, MN, respectively, in 2014 to 2016. Fall and preplant applications of N were applied at recommended and 125% of recommended rates (RN) according to University of Minnesota guidelines. Split-application treatments included a two-way (Sp, applied at 75% and 100% of RN) and a three-way split (TSp applied at 50%, 75%, and 100% of RN), with the total N rate equally split among application times. At Becker, maize grain yield with TSp was 12.6 to 15.7 Mg ha-1 among years and significantly greater than that with fall or preplant treatments. The TSp treatment also improved agronomic efficiency (AE) and recovery efficiency (RE) by an average of 30% over fall or preplant treatments. At Lamberton, maize grain yield, AE and RE did not differ among treatments. However, TSp75 improved AE by 8.3 kg kg-1 while producing comparable yields to fall and preplant treatments. At Waseca, Sp or TSp improved grain yield and AE compared with fall treatments. These results suggest that split applications of N can increase maize grain yield, AE, and RE on irrigated coarse-textured soils and applying N fertilizer near planting or as a split application can improve N management on non-irrigated clay loam soils.

Made available in DSpace on 2022-05-01T05:29:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Sustainable management strategies are needed to improve agronomic efficiency and cereal yield production under harsh abiotic climatic conditions such as in tropical Savannah. Under these environments, field-grown crops are usually exposed to drought and high temperature conditions. Silicon (Si) application could be a useful and sustainable strategy to enhance agronomic N use efficiency, leading to better cereal development. This study was developed to explore the effect of Si application as a soil amendment source (Ca and Mg silicate) associated with N levels applied in a side-dressing (control, low, medium and high N levels) on maize and wheat development, N uptake, agronomic efficiency and grain yield. The field experiments were carried out during four cropping seasons, using two soil amendment sources (Ca and Mg silicate and dolomitic limestone) and four N levels (0, 50, 100 and 200 kg N ha−1). The following evaluations were performed in maize and wheat crops: the shoots and roots biomass, total N, N-NO3−, N-NH4+ and Si accumulation in the shoots, roots and grain tissue, leaf chlorophyll index, grain yield and agronomic efficiency. The silicon amendment application enhanced leaf chlorophyll index, agronomic efficiency and N-uptake in maize and wheat plants, benefiting shoots and roots development and leading to a higher grain yield (an increase of 5.2 and 7.6%, respectively). It would be possible to reduce N fertilization in maize from 185–180 to 100 kg N ha−1 while maintaining similar grain yield with Si application. Additionally, Si application would reduce N fertilization in wheat from 195–200 to 100 kg N ha−1. Silicon application could be a key technology for improving plant-soil N-management, especially in Si accumulator crops, leading to a more sustainable cereal production under tropical conditions. Center for Nuclear Energy in Agriculture (CENA) University of São Paulo (USP) Department of Soil Water and Climate Southwest Research and Outreach Center (SWROC) University of Minnesota (UMN) Department of Plant Health Rural Engineering and Soils (DEFERS) São Paulo State University (UNESP) Department of Plant Health Rural Engineering and Soils (DEFERS) São Paulo State University (UNESP) FAPESP: 2017/06002-6 CNPq: 312359/2017-9

Field scale experiments are seldom replicated due to size constraints and limitations of other resources. This presents a difficulty in performing statistical analysis and interpretation of the results collected. In this paper we will evaluate water and nutrient effluent data from two fields, one managed under controlled subsurface drainage (CSSD) compared with an adjacent field under conventional free subsurface drainage (FSSD). The purpose of this paper is to compare approaches for statistical analysis of unreplicated paired design drainage experiments. The methods tested include the paired watershed design, a before-after control-impact paired (BACIP) design, time-series, and analysis using a beta and a gamma distribution. The assumptions used in the paired watershed and BACIP designs require the data to follow a normal distribution with identically and independently distributed errors, while the beta and gamma distributions do not require the assumption of normality. Analysis of the data set using a normal distribution was found to be inappropriate due to the nature of the data set which violates the assumptions required for analysis of variance; whereas, the analysis of the data using a beta distribution was found to produce the most appropriate results. The time series approach mimicked the physical treatments applied to FSSD and CSSD fields and led to a significant effect of CSSD compared to FSSD. Future work should focus on confirming that the beta distribution or time series are the best approaches for statistical analysis of field scale unreplicated paired design drainage experiments.

This study was developed to provide initial information on the chemical distribution of P into the different soil P pools after a soil sample underwent P sorption using 17 soil samples from the United States (13) and Brazil (4). During the sorption phase, soil samples were equilibrated with solutions containing increasing P concentrations (0–75 mg P L–¹) following standard procedures. Following the sorption phase, the soil samples were allowed to air dry for 72 h and underwent a chemical fractionation (in water, anionic resin, 0.5M NaHCO₃, 0.1M NaOH, and 1.0M HCl). A wide range of sorption strength ranging from 0.043 to 0.289 L kg–¹ and a maximum sorption ranging from 189 to 789 mg kg–¹ were observed. More than 59% of the sorbed P was found in the water + resin fraction, which is considered the most labile pools where the binding energy is assumed to be low. In contrast, less than 25% of the sorbed P was found in the nonlabile pools where the binding energy is assumed to be the greatest. Although less than 25% of the sorbed P was found in the non-labile pools, the NaOH+HCl fraction contributed 2 to 61% of the overall sorption strength estimated for the soils studied. The results of this study suggest that sorption strength calculated from sorption studies are heavily skewed toward the nonlabile fraction, which was found to constitute a very small portion of the binding sites occupied during sorption studies.

Water extractable organic carbon (WEOC) and nitrogen (WEON) are two key parameters of soil water extractable organic matter (WEOM). Proper management of manure application rate in combination with tillage and cropping management could maintain appropriate WEOC and WEON concentrations in soils while decreasing the risk of their runoff from cropland and pastures. The objective of this research was to determine the effect of poultry litter (PL) application on WEOC and WEON in soils under different crops, tillage regimes, and grazing strategies. From 2001 to 2012, PL was applied at multiple rates to cultivated fields in a corn-oat/wheat-hay rotation or to pastures grazed by cattle or ungrazed. Soil samples (0 - 15 cm) were analyzed for KCl-extractable mineral N, and WEOC, and WEON contents. In addition, Ultraviolet-visible (UV-vis) and fluorescence spectroscopies were used to characterize WEOC stability. Organic N levels were higher at the high PL application rates. The soil C:N ratio narrowed as the PL application rate increased. However, the soil from pastures which received PL tended to have a wider range of C:N ratios than soil from the cultivated fields, despite identical PL application rates. The spectral analyses indicated that WEOC properties were responsive to management and PL application rate; therefore, this parameter may be used as a guide to provide best management strategy for manure application.

Animal manure consists of predominantly urine and feces, but also may contain bedding materials, dropped feed, scurf, and other farming wastes. Manure is typically applied to soils as fertilizer for agricultural production. The estimated amount of manure produced in 12 major livestock-producing countries is 9 × 109 Mg of manure annually. Manure is rich in plant nutrients. However, manure is also considered as an environmental pollutant when it is over-applied to cropland or following runoff into surface water. Manure can also influence global climate change via emissions of methane (CH4) and nitrous oxide (N2O). Thus, increased and updated knowledge of applied and environmental chemistry of animal manure is needed to shed light on the research and development of animal manure utilization and minimization of its adverse environmental concerns. The advances in basic and applied studies of manure major components, organic matter, phosphorus, and nitrogen, primarily related to US livestock production are summarized in this review. Detailed focus was placed on three notable challenges for future manure research: 1) soil application of animal manure, 2) manure phytate phosphorus, and 3) manure nitrogen availability. This review may contribute to the global effort in sustainable and environmentally sound agriculture by stimulating new ideas and directions in animal manure research, and promoting application of knowledge and insight derived from manure research into improved manure management strategies.

Sequential fractionation coupled with phosphatase hydrolysis allows a greater understanding of the effects of animal manure on the chemical distribution of soil P. Concentrations of specific soil P fractions were determined after long-term (>10 yr) poultry litter application at rates of 4.5, 6.7, 9.0, 11.2, and 13.4 Mg manure ha⁻¹ yr⁻¹ to watershed-scale plots (cultivated and grazed–ungrazed pasture) on a calcareous Texas Blackland Vertisol. Soil total extractable P (Pₜ) and inorganic P (Pᵢ) were quantified following sequential extraction with H₂O, NaHCO₃, NaOH, and HCl. Hydrolyzable organic P (Pₑ) and non-hydrolyzable organic P (Pₙₑ) were determined in the extracted fractions following enzymatic hydrolysis. Litter application increased Pₜ regardless of land-use type compared with the control. Concentrations of H₂O-extractable Pᵢ in litter-amended plots increased by 9 to 34% (cultivated) and 7 to 30% (pasture) over the control, indicating substantial risk of soluble P runoff. Labile organic P (Pₒ) extracted with H₂O and NaHCO₃ decreased in the order monoester > nucleic acid > phytate > Pₙₑ. An average of 68% of Pₜ was extractable with HCl. Organic P comprised the majority (95%) of HCl-Pₜ; however, only trace levels of HCl-Pₒ were hydrolyzable, and litter application increased HCl-Pₙₑ up to 217%. Thus, litter application increased levels of both soluble Pᵢ and stable Pₙₑ, but the specific response varied with application rate and land management. This study increased understanding of P chemical distribution with time in litter-amended soil with high clay and CaCO₃ contents under differing land-use scenarios.

The fertilizer industry has attempted to increase P mobility and lability after fertilizer application by using nonconventional phosphates or by including additives in the fertilizer formulation. We incubated granular monoammonium phosphate (MAP), sulfur-coated MAP, humic acid-coated MAP, triple superphosphate (TSP), ammonium potassium polyphosphate (AKPP), and ammonium magnesium phosphate (struvite) with soils from the United States and Brazil in Petri dishes for 56 d. We estimated P mobility by measuring P movement away from fertilizer granules and assessed P lability through sequential chemical fractionation of soil collected from the dishes. In addition, we monitored the change in soil pH with distance from fertilizer placed in the Petri dish. Soil pH changed in response to fertilizer additions as a function of initial soil pH. In fertilized soils, the soil pH response followed a quadratic function as the distance from the fertilizer placement site increased. Soil characteristics influenced P mobility, with mobility decreasing from the Hubbard (12% clay; pH 5.3), to Brazil (20% clay; pH 6.5), to Normania (22% clay; pH 5.5), and then Barnes (31% clay; pH 8.0) soil. The use of MAP-based fertilizers resulted in the greatest mobility, while struvite provided the lowest mobility. In contrast, struvite granules dissolved the least resulting in the highest labile P concentrations, due to direct extraction of fertilizer P from undissolved granules (average of 73% of applied P). Comparatively, TSP provided the lowest amount of labile P (average of 52% applied P). Sulfur and humic acid-coated MAP had no effect on P lability or mobility.

Made available in DSpace on 2018-12-11T17:20:35Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-12-01 A better understanding of widespread agricultural practices adopted in the region of Ribeira Valley, São Paulo, Brazil for upland rice (Oryza sativa L.) production is needed. The objectives of this study were to determine the optimum sowing date and highest yielding genotypes for rice production. Treatments included four upland rice genotypes (ANA 5011, AN-Cambará, Moti-Amarelo, and Moti-Branco) and four sowing dates (October, November, December, and January) in 2011 and 2012. The results of the study showed that genotype ANA 5011 had the earliest maturity, while the Moti genotypes had the latest maturity in all sowing dates. The Moti genotypes were found to have greater plant height and 1,000-grain weight than the other two genotypes. In contrast, the Moti genotypes had fewer panicles m-2, fewer total filled and total numbers of spikelets panicle-1, and lower final yield. The genotype AN-Cambará had the highest number of tillers, filled and total number of spikelets panicle-1, panicle m-2, and the highest yield. Sowing in either November or December was found to be the most suitable dates for rice cultivation for all genotypes. In conclusion, the AN-Cambará genotype was found to have the highest yield potential for the region among all genotypes studied. Departamento de Fitotecnia Unesp Universidade Estadual Paulista Campus de Dracena, Rodovia Comandante Joao Ribeiro de Barros, km 651 Department of Soil Water and Climate University of Minnesota Southwest Research and Outreach Center, 23669 130th Departamento de Fitotecnia Unesp Universidade Estadual Paulista Campus de Registro, Avenida Nelson Brihi Badur, 430 Departamento de Fitotecnia Unesp Universidade Estadual Paulista Campus de Dracena, Rodovia Comandante Joao Ribeiro de Barros, km 651 Departamento de Fitotecnia Unesp Universidade Estadual Paulista Campus de Registro, Avenida Nelson Brihi Badur, 430

Soil hydrophobicity is a characteristic that some soils exhibit where they repel water, and the plant community may play a role in its development. In the Lower Wisconsin River Valley (LWRV), some land with prairie has been planted with pines. There is an undetermined soil water repellency consequence of this land use change, as it was discovered that under pine plantation the soil was so desiccated at certain periods that it became extremely hydrophobic. The objective of this study was to determine the extent of soil hydrophobicity of Sparta sand (sandy, mixed, mesic Entic Hapludoll) in the LWRV under three vegetation types: prairie, pine plantation, and mixed prairie/forest (mixed vegetation). Soil samples were collected in 5-cm increments to a depth of 50 cm. Samples were analyzed using water drop penetration time (WDPT), soil wetted area (SWA), and molarity of ethanol (MED). Soil particle-size distribution (PSD), soil organic carbon (SOC), and soil water content were also determined. Additional surface samples were analyzed for chemical and particulate organic matter (POM) fractionation. Hydrophobicity was greater and extended to deeper depths in the pine plantation (35-cm depth) than in the prairie and mixed vegetations (10-cm depth). The greater water repellency in the pine resulted in drier soil conditions. This suggests there are strong plant-soil- hydrophobicity interactions for this soil. The PSD was not significantly different across vegetation, although it was across soil depth; this is expected since the soil parent materials were not different across sites. The SOC significantly decreased with depth but was not significantly different among vegetations. There were no relationships between water repellency, humic substances, and POM. A possible factor for the difference in soil water repellency among vegetations could be the quality of soil organic matter (SOM) produced by the different vegetation, with pine being the greater producer of hydrophobic material.

In this research, a sequential fractionation procedure coupled with enzyme hydrolysis was used to categorize the phosphorus (P) forms of 18 manure samples collected from in-barn composted bedded pack (beef manure), anaerobic digestion with liquid–solid separation (dairy manure), and liquid–solid separation systems (dairy manure). This research also determined the effects of those P forms on the increase in soil test P (STP) of five soil series. The soils used had initial Bray-1 P ranging from 16 to 43 mg P kg−1. Total dry-ash P (Pt) of the manures ranged from 1.4 to 15.0 g P kg−1; total inorganic P (Pit) accounted for 20 to 81 % of Pt; and enzymatically hydrolysable P (Pet) accounted for 5 to 26 % of Pt. Liquid–solid separation tended to concentrate the manure P in the liquid fractions. In contrast, anaerobic digestion did not affect the manure P distribution compared with the undigested raw manure from the same system. No differences in P distribution were found for the compost bedded pack manure. In the soil incubation study, manure and fertilizer were applied at 40 mg total P kg−1. Separated liquid manure from two systems tended to increase STP more than the separated solid manures from the same systems. Although anaerobic digestion modified some of the physical and chemical properties of the treated manures, it did not clearly impact how digested manure increased STP compared with the raw manures. Overall, the increase in STP after treated manure application was found to be a function of soil clay content and manure Pit + Pet applied.

The Mehlich-3 soil test is extensively used to determine available soil P; however, calibration studies for sand greens are lacking. The purpose of this field study was to evaluate turfgrass response to different soil test P (STP) levels and application of trinexapac-ethyl (TE) (0.1 kg a.i. ha⁻¹ every 200 growing degree days). A creeping bentgrass (Agrostis stolonifera L. ‘Penn A4’) putting green was constructed at the O.J. Noer Turfgrass Research and Education Facility in Madison, WI, using 30 cm of calcareous sand overlaying pea gravel. A factorial of four STP levels, 0 to 95 mg P kg⁻¹, was established with monopotassium phosphate (MKP) with or without TE was arranged in a randomized complete block design with four replicates. Mehlich-3 STP level, clipping yield, tissue P content, and visual turfgrass quality were quantified monthly for two growing seasons. Nonlinear regression analysis was used to calculate STP and tissue P content critical points. Although a wide range of initial STP was established, STP levels in all treatments declined substantially during the two season study, eventually stabilizing to approximately 3 to 5 mg P kg⁻¹. Turfgrass quality was the most sensitive to both STP and tissue P content and provided clear critical values with linear plateau regression. The Mehlich-3 STP and tissue P content critical points for visual turfgrass quality ranged from 6 to 11 mg kg⁻¹ and 1.5 to 4.4 g kg⁻¹, respectively. While TE sometimes statistically altered the STP critical point, the difference was not substantial enough to suggest different STP recommendations for turf maintained with or without TE.

The most viable way to beneficially use animal manure on most farms is land application. Over the past few decades, repeated manure application has shown adverse effects on environmental quality due to phosphorus (P) runoff with rainwater, leading to eutrophication of aquatic ecosystems. Improved understanding of manure P chemistry may reduce this risk. In this research, 42 manure samples from seven animal species (beef and dairy cattle, swine, chicken, turkey, dairy goat, horse, and sheep) were sequentially fractionated with water, NaHCO₃, NaOH, and HCl. Inorganic (P(i)), organic (P(o)), enzymatic hydrolyzable (P(e); monoester-, DNA-, and phytate-like P), and nonhydrolyzable P were measured in each fraction. Total dry ash P (P(t)) was measured in all manures. Total fractionated P (P(ft)) and total P(i) (P(it)) showed a strong linear relationship with P(t). However, the ratios between P(ft)/P(t) and P(it)/P(t) varied from 59 to 117% and from 28 to 96%, respectively. Water and NaHCO₃ extracted most of the P(i) in manure from ruminant+horse, whereas in nonruminant species a large fraction of manure P was extracted in the HCl fraction. Manure P(e) summed over all fractions (P(et)) accounted for 41 to 69% of total P(0) and 4 to 29% of P(t). The hydrolyzable pool in the majority of the manures was dominated by phytate- and DNA-like P in water, monoester- and DNA-like P in NaHCO₃, and monoester- and phytate-like P in NaOH and HCl fractions. In conclusion, if one assumes that the P(et) and P(it) from the fractionation can become bioavailable, then from 34 to 100% of P(t) in animal manure would be bioavailable. This suggests the need for frequent monitoring of manure P for better manure management practices.

This laboratory study was conducted to evaluate the potential of nine manure samples from dairy (n = 7), beef (n = 1), and swine (n = 1) to cause water repellency (WR) in six soils; in addition, the duration of WR in two soils was assessed in an incubation study. Manures were applied to supp

Water repellency or hydrophobicity in soil is a widespread condition found in soils around the world. Some effects of water repellency in soil are decreases in wetting front movement and water infiltration and preferential flow of water and solutes. The water drop penetration time (WDPT) met

During the incineration of turkey manure, a wide variety and concentration of nutrients are conserved in the turkey manure ash (TMA). In particular, the high concentration of citrate-soluble phosphorus (P) (43 g kg−1) may make it a suitable P source for crop production. The ash is alkaline with a pH of 12.2. We conducted a soil incubation study using a low-P soil with a pH of 6.2 to evaluate the effects of TMA on soil pH and extractable P. Two TMA rates, based on citrate-soluble P (10.9 and 21.9 mg kg−1), were compared with equivalent rates of triple superphosphate (TSP). In addition, a 0-P control was included. At the rates tested, TMA slightly increased soil pH, but this increase would be of minor agronomic importance. At equivalent P rates, changes in water-soluble P (WSP) concentrations with TMA and TSP were similar. Changes in iron-oxide-strip–extractable P (FeO P) and Bray 1 P concentrations were greater with TMA than with TSP. In contrast, changes in Olsen P concentrations were greater with TSP tha...

Incinerating turkey manure is a new option in the USA to generate renewable energy and to eliminate environmental problems associated with manure stockpiling. Incineration produces turkey manure ash (TMA) with a nutrient content of 43 g phosphorus (P) kg−1 and 100 g potassium (K) kg−1. We conducted a greenhouse pot study using a low P (6 mg kg−1) and high K (121 mg kg−1) soil/sand mixture with a 7.0 pH to evaluate early growth response of corn (Zea mays L.) to TMA. A control and five rates based on P (5.6, 10.9, 16.5, 21.9, and 27.2 mg kg−1) and respective K contents in TMA were compared with triple-superphosphate and potassium chloride fertilizer. Plant height and stalk thickness at 24 and 31 days after emergence (DAE) were greatest with the fertilizer, but no differences were detected at the final sampling (52 DAE). Regardless of nutrient source, plant biomass increased with P rate. Because of faster initial plant development, corn dry matter 52 DAE was 15 to 20% greater with fertilizer than with TMA. C...

A power plant that utilizes turkey manure as fuel to produce energy was built in Benson, Minnesota, and started full energy production in 2007. The plant was built to meet legislative requirements governing the use of renewable sources to generate energy in Minnesota. Although the use of turkey manure as biofuel generates energy, it also results in turkey manure ash (TMA) as a by‐product that contains phosphorus (P), potassium (K), sulfur (S), and zinc (Z) as well as other essential and nonessential elements. A 2‐year study was conducted to compare TMA with triple‐superphosphate and potassium chloride fertilizers as a source of nutrients for alfalfa (Medicago sativa) at three locations: Lamberton, Morris, and Appleton, Minnesota. The soils at Lamberton and Appleton were acidic with P and K concentrations ranging from medium‐high to very high, whereas the soil at Morris was alkaline with high concentrations of P and K. The experiment consisted of a control (0 P and 0 K) and annual and split applications of...

Sequential fractionation has helped improving our understanding of the lability and bioavailability of P in soil. Nevertheless, there have been no reports on how manipulation of the different fractions prior to analyses affects the total P (TP) concentrations measured. This study investigated the effects of sample digestion, filtration and acidification on the TP concentrations determined by ICP-OES in 20 soil samples. Total P in extracts were either determined without digestion by ICP-OES, or ICP-OES following block digestion, or autoclave digestion. The effects of sample filtration and acidification on undigested alkaline extracts prior to ICP-OES were also evaluated. Results showed that, TP concentrations were greatest in the block-digested extracts, though the variability introduced by the block-digestion was the highest. Acidification of NaHCO3 extracts resulted in lower TP concentrations, while acidification of NaOH randomly increased or decreased TP concentrations. The precision observed with ICP-OES of undigested extracts suggests this should be the preferred method for TP determination in sequentially extracted samples. Thus, observations reported in this work would be helpful in appropriate sample handling for P determination, thereby improving the precision of P determination. The results are also useful for literature data comparison and discussion when there are differences in sample treatments.