Risk and Nitrogen Application Decisions in Florida Potato Production

This study focuses on development of agricultural best management practices (BMPs) for potato production areas in Northeast Florida, and presents the results of the initial situation assessment. BMP implementation is the primary strategy used by agencies and farmers to improve the efficiency and to ensure environmental sustainability of agricultural production. Although BMPs are defined as “economically feasible” and “cost-effective”, economic analysis conducted as a part of BMP development has been limited, leaving the room for disagreement about economic impacts of specific BMPs. As a part of the situation assessment, we used interviews, group discussions, a survey, and a field trip to collect information about farmers’ production practices and to examine farmers’ opinions about BMP development process. Then, partial budget analysis was used determine the relative impacts of various factors (including the implementation of nitrogen fertilization management BMP) on production returns. Finally, an economic model is proposed to incorporate production risk analysis in BMP evaluation process.Florida potato production, partial budget analysis, risk analysis, best management practice, nitrogen fertilization, Agribusiness, Agricultural and Food Policy, Crop Production/Industries, Environmental Economics and Policy, Farm Management, Production Economics, Risk and Uncertainty,

Enhanced Agronomic Efficiency Using a New Controlled-Released, Polymeric-Coated Nitrogen Fertilizer in Rice

[EN] Fertilizer-use efficiency is one of the most critical concerns in rice cultivation to reduce N losses, increase yields, and improve crop management. The e ects of a new polymeric-coated controlled-release fertilizer (CRF) were compared to those of other slow-release and traditional fertilizers in a microscale experiment, which was carried out in cuvettes under partly controlled ambient conditions, and a large-scale field experiment. To evaluate the fertilizer¿s efficiency, nitrogen and water-use efficiency were calculated using the measurement of different photosynthetic and crop yield parameters. Improved responses regarding some of the analyzed physiological and growth parameters were observed for those plants fertilized with the new CRF. In the microscale experiment, significantly increased yields (ca. 35%) were produced in the plants treated with CRF as compared to traditional fertilizer. These results were in accordance with ca. 24% significant increased levels of N in leaves of CRF-treated plants, besides increased P, Fe, Mn, and cytokinin contents. At the field scale, similar yields were obtained with the slow-release or traditional fertilizers and CRF at a 20% reduced N dose. The new controlled-release fertilizer is a urea-based fertilizer coated with lignosulfonates, which is cheaply produced from the waste of pulp and wood industries, containing humic acids as biostimulants. In conclusion, CRF is recommended to facilitate rice crop management and to reduce contamination, as it can be formulated with lower N doses and because it is ecological manufacturing.This research was funded by the Spanish Ministry of Economy and Competitiveness, grant number RTC-2014-1457-5, with the project entitled "Los CRFs como alternativa a los fertilizantes tradicionales: buscando una mayor proteccion del medio ambiente" ("CRFs as alternative to traditional fertilizers: looking for a better protection of the environment").Gil-Ortiz, R.; Naranjo, MÁ.; Ruiz-Navarro, A.; Atares, S.; García, C.; Zotarelli, L.; San Bautista Primo, A.... (2020). Enhanced Agronomic Efficiency Using a New Controlled-Released, Polymeric-Coated Nitrogen Fertilizer in Rice. Plants. 9(9):1-17. https://doi.org/10.3390/plants9091183S1179

Sistema radicular da soja em função da compactação do solo no sistema de plantio direto

An experiment was carried out on a Rhodic Ferralsol, in Londrina, PR, to evaluate the soil compaction effects on soil morphostructure and on soybean root distribution, under no-tillage system. The field experiment was arranged in a completely randomized block (split plot) design with four replicates, and with the compacted treatments in the main plots and soybean varieties in subplots. The treatments were: one scarified soil until 20–25 cm depth layer with bulk density of 1.17 Mg m-3, and one compacted soil with bulk density of 1.38 Mg m-3, in a 12 cm depth. Two varieties of soybean, Embrapa-4 and BR-16, were cultivated on subplots. Roots developed in zones with less resistance of penetration and in biological tunnels. The soybean grain yield was not different under compacted and noncompacted soil, because soil water moisture was adequate. Embrapa-4 showed greater root density than BR-16.O objetivo deste trabalho foi avaliar os efeitos da compactação do solo sobre suas propriedades morfoestruturais e sobre o desenvolvimento radicular da soja, sob sistema plantio direto, em um experimento conduzido num Latossolo Vermelho distroférrico, em Londrina, PR. O delineamento utilizado foi o de blocos ao acaso, com parcelas subdivididas e quatro repetições. Foram constituídos dois tratamentos de manejo nas parcelas: um em solo escarificado à profundidade de 20–25 cm, com densidade do solo de 1,17 Mg m-3; e outro em solo compactado, a 12 cm de profundidade, e densidade de 1,38 Mg m-3. Nas subparcelas, foram semeadas duas cultivares de soja, Embrapa-4 e BR-16. A presença de camadas mais compactas no perfil do solo provocou o desenvolvimento radicular em zonas de menor resistência, em poros biológicos e nas fissuras do solo. A produção de grãos não apresentou diferença entre os tratamentos, graças à adequada disponibilidade hídrica durante o período avaliado. A cultivar Embrapa-4 apresentou maior crescimento radicular em estruturas compactas, comparada à cultivar BR-16

Calibration of a Minolta SPAD-502 chlorophyll meter for evaluation of the nitrogen nutrition of maize

O objetivo deste trabalho foi calibrar o medidor de clorofila Minolta SPAD-502 para avaliação da nutrição nitrogenada das plantas de milho, baseando-se na prévia comparação das leituras de clorofila com os teores obtidos pelos extratores N,N-dimetilformamida (DMF) e acetona 80%. No campo, foram avaliados os teores de clorofila em folhas de milho cultivado sob plantio direto após a cultura de aveia-preta e após a de tremoço-branco, por duas safras consecutivas. A extração da clorofila com a solução DMF, por 72 horas, foi a mais indicada para a calibração do medidor de clorofila SPAD-502 na cultura do milho. O ajuste do modelo linear expressou melhor a relação entre o conteúdo de clorofila e as leituras do SPAD na cultura do milho, e seu uso produziu resultados coerentes com o estado nutricional da cultura.The subject of this study was the calibration of a Minolta SPAD-502 chlorophyll meter for evaluation of the N nutrition of maize, firstly comparing the chlorophyll readings to the contents obtained from either 80% acetone or N,N-dimethylformamide (DMF) chlorophyll extrators. The chlorophyll of the maize leaves cultivated under zero-tillage after oat and lupin for two consecutive harvests was evaluated in a field experiment. The chlorophyll extraction after 72 hours in DMF solution, was the most suitable for the calibration of the SPAD-502 chlorophyll meter for maize and its use was coherent with the nutritional status of the crop

Potato Breeding and Variety Development for Improved Quality and Pest Resistance in the Eastern United States

The eastern U.S. potato industry needs new potato varieties to overcome pest problems while reducing agricultural chemical use and to enhance marketing opportunities. This project will conduct potato breeding, germplasm enhancement, and selection studies to improve potato productivity and quality for important eastern U.S. markets. Novel and highly improved potato germplasm and varieties will be developed to reduce the impact of economically important potato pests, such as golden nematode, late blight, pink rot, and scab

Fixação biológica de nitrogênio e fertilizantes nitrogenados no balanço de nitrogênio em soja, milho e algodão

The subject of this work was to evaluate the effect of biological nitrogen fixation (BNF) of soybean, and the nitrogen fertilizer use efficiency (NFUE) by maize and cotton, on the N balance of an Oxisol (Typic Haplorthox) under no-tillage, in Dourados, MS. The study was carried out for two consecutive years, focusing the summer crops. The BNF contribution to soybean was evaluated by the 15N natural abundance technique. The NFUE was evaluated by the substitution of conventional N fertilizers used for maize and cotton crops by 15N enriched ones. In the first year, both crops were fertilized with 115 kg N ha-1 split in three doses; only plant aerial parts were evaluated. In the second year, only the maize crop was evaluated and received 70 kg ha-1 N, as a dressing fertilization at 29 DAE. In that year, the aerial part of maize plants and the soil of a 0–20 cm layer were evaluated. For two consecutive harvests, the BNF contribution to soybean was over 80%, bringing about high yields and a positive N balance to the soil. In the first year, NFUE for aerial parts of maize and cotton were 48 and 61%, respectively. In the second year, NFUE for maize was 46%, and the soil layer of 0–20 cm also retained 24% of de N fertilizer applied. For the yield levels of maize and cotton, the fertilizer management results in negative N balances to the soil.O objetivo deste trabalho foi avaliar os efeitos da fixação biológica de nitrogênio (FBN) da cultura da soja, e a eficiência do uso de fertilizantes nitrogenados (EUFN) pelas culturas de milho e algodão, no balanço de N de um Latossolo Vermelho distroférrico, sob plantio direto, em Dourados, MS. O estudo foi feito em dois anos, concentrando-se nas safras de verão. A contribuição da FBN para a soja foi avaliada pela técnica de abundância natural de 15N. A EUFN foi avaliada mediante a substituição dos fertilizantes nitrogenados convencionais pelos enriquecidos com 15N, nas culturas do milho e algodão. No primeiro ano, foram adicionados 115 kg ha-1 de N, de forma parcelada, para ambas as culturas; somente a parte aérea das plantas foi avaliada. No segundo ano, somente a cultura do milho foi avaliada, tendo recebido 70 kg ha-1 de N aos 29 DAE. Nesse ano, além da parte aérea do milho, amostrou-se também o solo, na profundidade de 0–20 cm. Nos dois anos de avaliação, a FBN foi superior a 80% do N nas plantas de soja, o que resultou em alta produtividade e em balanço positivo de N para o solo. A EUFN na parte aérea de milho e algodão, no primeiro ano, foi de 48 e 61%, respectivamente. No segundo ano, a EUFN, na parte aérea do milho, foi de 46%, tendo-se observado que 24% do N do fertilizante permaneceu nos primeiros 20 cm de solo. Para os níveis de produtividade das culturas de milho e algodão, o manejo do fertilizante nitrogenado resulta em balanços negativos de N para o solo

Evaluating the impact of modeling the family effect for clonal selection in potato-breeding programs

Because of its wide distribution, high yield potential, and short cycle, the potato has become essential for global food security. However, the complexity of tetrasomic inheritance, the high level of heterozygosity of the parents, the low multiplication rate of tubers, and the genotype-by-environment interactions impose severe challenges on tetraploid potato–breeding programs. The initial stages of selection take place in experiments with low selection accuracy for many of the quantitative traits of interest, for example, tuber yield. The goal of this study was to investigate the contribution of incorporating a family effect in the estimation of the total genotypic effect and selection of clones in the initial stage of a potato-breeding program. The evaluation included single trials (STs) and multi-environment trials (METs). A total of 1,280 clones from 67 full-sib families from the potato-breeding program at Universidade Federal de Lavras were evaluated for the traits total tuber yield and specific gravity. These clones were distributed in six evaluated trials that varied according to the heat stress level: without heat stress, moderate heat stress, and high heat stress. To verify the importance of the family effect, models with and without the family effect were compared for the analysis of ST and MET data for both traits. The models that included the family effect were better adjusted in the ST and MET data analyses for both traits, except when the family effect was not significant. Furthermore, the inclusion of the family effect increased the selective efficiency of clones in both ST and MET analyses via an increase in the accuracy of the total genotypic value. These same models also allowed the prediction of clone effects more realistically, as the variance components associated with family and clone effects within a family were not confounded. Thus, clonal selection based on the total genotypic value, combining the effects of family and clones within a family, proved to be a good alternative for potato-breeding programs that can accommodate the logistic and data tracking required in the breeding program

Risk and Nitrogen Application Decisions in Florida Potato Production

This study focuses on development of agricultural best management practices (BMPs) for potato production areas in Northeast Florida, and presents the results of the initial situation assessment. BMP implementation is the primary strategy used by agencies and farmers to improve the efficiency and to ensure environmental sustainability of agricultural production. Although BMPs are defined as “economically feasible” and “cost-effective”, economic analysis conducted as a part of BMP development has been limited, leaving the room for disagreement about economic impacts of specific BMPs. As a part of the situation assessment, we used interviews, group discussions, a survey, and a field trip to collect information about farmers’ production practices and to examine farmers’ opinions about BMP development process. Then, partial budget analysis was used determine the relative impacts of various factors (including the implementation of nitrogen fertilization management BMP) on production returns. Finally, an economic model is proposed to incorporate production risk analysis in BMP evaluation process