Respuesta de tomate (Solanum lycopersicum L.) a la fertilización con nitrógeno y aplicación de composta.

The effects of municipal biosolid yard-waste compost and fertilizer N applications on tomato (Solanum lycopersicum L.) growth, yield and fruit quality were evaluated in Lajas (Typic Haplusterts) and Juana Díaz (Cumulic Haplustolls) (Fortuna Substation), Puerto Rico, for three years. In Fortuna, an initial application of compost at 50 t/ha significantly improved yields over those in unamended soil, yet a second application of compost the following year at 50 and 100 t/ha, reduced yields. No residual effect of compost on tomato yields was detected the third year. In Fortuna, levels of N fertilization did not significantly affect tomato yields, growth or quality, except in the third year, when tomato yields were significantly higher in soils fertilized with 75 kg N/ha than yields from unfertilized soil. At Lajas, there was a significant crop response to fertilizer N in one of the two site years, when crop response to initial fertilizer N application was evaluated. Compost addition in Lajas did not improve yields or plant agronomic components for the first year of cropping tomato. The use of the SPAD chlorophyll meter may be a useful N diagnostic tool for tomato grown under drip irrigation and polyethylene mulch. In general, maximum SPAD values coincided with maximum yields, depending on the hybrid or variety planted; treatment effects were adequately separated out. The economic optimum N rate was relatively insensitive to fertilizer and tomato price fluctuations in the range selected. The calculated optimum N rate to achieve 99% yield goals was 143 kg N/ha, at sites with initial N application in Lajas, and 165 kg N/ha, respectively, for second and third applications of N in Fortuna, with maximum yields near 54 t/ha.Por tres años se evaluaron los efectos de composta producida a partir de residuos vegetales y biosólidos, y de nitrógeno inorgánico en el crecimiento, rendimiento y calidad de fruta de tomate en las Subestaciones de Lajas (Typic Haplusterts) y Juana Díaz (Cumulic Haplustolls) (Subestación de Fortuna), Puerto Rico. En Fortuna, la aplicación de 50 t/ha aumentó el rendimiento sobre suelo sin enmendar pero una segunda aplicación de 50 y 100 t/ha redujo los rendimientos. No hubo un efecto residual de la composta en el tercer año. Los niveles de fertilización no incrementaron significativamente los rendimientos excepto en el tercer año, cuando los mayores rendimientos se obtuvieron con la aplicación de 75 kg N/ha en forma de fertilizante inorgánico. En Lajas, hubo respuesta a la fertilización inicial en uno de los dos sitios-años. La adición de composta no mejoró los rendimientos ni los componentes agronómicos del tomate. El uso del medidor de clorofila SPAD puede ser útil para la producción de tomate cultivado en bancos elevados, con plástico y riego por goteo porque los valores máximos de SPAD coincidieron con los mayores rendimientos obtenidos. La medida sirvió para evaluar el efecto de los tratamientos, aunque los resultados dependen de la variedad o híbrido utilizado. El nivel óptimo económico obtenido fue poco sensitivo a los precios de fertilizante y tomate seleccionado. El nivel óptimo de fertilización de N para obtener el 99% de rendimiento máximo fue 143 kg N/ha en áreas que recibieron aplicaciones iniciales de N en Lajas, y 165 kg N/ha en áreas con más de un año bajo el cultivo de tomate en Fortuna, con rendimientos cerca de 54 t/ha

INFLUENCE OF IMMATURE COMPOST ON GROWTH AND YIELD OF TOMATO

Economics often encourage utilization of compost without a curing period. Tomato (Lycopersicon esculentum, Mill.) transplants were set into field plots 4,11, 19, 35, and 70 days after incorporation of uncured biosolids/yard trimming compost at 135 tha1, Dry weights of plants in control (nocompost) plots from the first transplant date and fresh weights of plants from the last transplant date were greater than from compost plots. Fruit yields of control and compost plots were similar. In greenhouse flats, mean days to emergence were similar between treatments, and total emergence percentages in compost were lower than in a sandy field soil, but similar to a commercial peat-lite germination mix, Seedling shoot weights were similar between treatments, but root weight was lower in the peat-lite mix than in compost or soil. In general, utilization of the uncured compost was not detrimental to tomato plant growth or fruit yields

Land Application of Biosolids in the USA: A Review

Land application of biosolids has proven a cost-effective method of waste disposal by beneficially recycling organic matter and nutrients and improving soil quality; however, it may also pose potential threat to the environment and human health. The purpose of this paper is to provide information on recent research progresses and regulation efforts regarding land application of biosolids, including forms and types and nutrient values of biosolids, environmental and health concerns, and related best management practices (BMPs) of biosolids application, with emphasis on its land application in agriculture. More research and regulations are expected to minimize potential risks of biosolids land application, especially its long-term impacts

Characteristics of translocation and remobilization of zinc absorbed from different stages into grain in dense rice genotype using a stable isotope tracing technique

Zinc (Zn) is an essential micronutrient for plant and human, and over 40% of children in the world are suffering from Zn malnutrition. Zinc deficiency in human is mainly caused from low Zn concentration and bioavailability in foods or edible parts of crop plants. Biofortification appears to be a most sustainable and cost-effective approach to solve human micronutrient malnutrition. Zinc deficiency is a widespread problem in rice, causing decreased crop yields and nutritional quality. Increasing Zn density in rice grain is important for improving crop yield and human nutrition. Large genotypic differences in Zn concentration in rice grains have been observed, however, the mechanisms of Zn dense acumulation in rice grain is not fully understood. In this paper, 68Zn stable isotope tracing technique was used to compare the translocation of 68Zn absorbed at different growth stages to grain and Zn remobilization between Zn-dense and Zn-indense rice genotype. The results showed that the Zn-dense rice genotype (IR68144) had greater translocation of 68Zn absorbed during early (from seedling to tillering stage) and late (from grain filling to harvest stage)growth stages, as compared with the indense genotype (IR64). More than half of Zn distributed in grains was translocated from those absorbed by rice plant before anthesis, accounting for 63% and 52% of the total for IR68144 and IR64, respectively. Even after grain filling, plenty of Zn could be transported into grains, with a two fold higher distribution rate to brown rice for IR68144 than for IR64. The Zn-indense rice genotype IR64 contained more 68Zn in roots whereas the Zn-dense rice genotype IR68144 contained more 68Zn in stems, leaves, and grains when 68Zn was supplied at all stages. The remobilization of 68Zn within the plant varied greatly between the two genotypes. When stopping 68Zn supplying at tillering stage, we found that more 68Zn was retranslocated into the new growing leaves and tillers, and more 68Zn was exported from the full-expanded leaf in the dense genotype than in the indense genotype. When stopping 68Zn supply at Anthesis stage, it was observed that more 68Zn was retranslocated into the growing grain, and more 68Zn remobilized from stem and flag leaf in IR68144 than in IR64. The retranslocation of 68Zn from the flag leaf to grain was found to be twice greater in IR68144 than in IR64 when applying 68Zn on the flag leaf either at booting stage or anthesis stage. These results indicated that the Zn-density in rice grain is closely associated with the ability of Zn translocation from “the source” to “the sink” at both early and late growth stages and phloem mobility of Zn, especially from stem to grain

Analysis of Bisphenol A, Nonylphenol, and Natural Estrogens in Vegetables and Fruits Using Gas Chromatography–Tandem Mass Spectrometry

Bisphenol A (BPA), nonylphenol (NP), and steroidal estrogens in vegetables and fruits were analyzed using gas chromatography with tandem mass spectrometry (GC-MS/MS). Isotope dilution standards were spiked before the extraction to account for extraction inefficiency and loss of analytes during sample workup. Recoveries were >90% for all of the compounds in each matrix. The limit of detection (LOD) ranged from 0.03 to 0.3 μg kg^–1, whereas the limit of quantitation (LOQ) ranged from 0.1 to 1.0 μg kg^–1. All analytes can be monitored in a single GC-MS/MS run with a run time of 20 min. Occurrence of these endocrine-disrupting chemicals (EDCs) in vegetables and fruits from local markets was observed using the established analytical method. BPA was detected in all vegetable and fruit samples, ranging from 0.2 ± 0.1 to 9.0 ± 4.9 μg kg^–1, indicating significant exposure potential for humans. NP was detected in pumpkin, sweet potato, citrus, and apple samples. The concentration of 4-n-NP ranged from 5.3 ± 2.4 to 18.9 ± 8.0 μg kg^–1, whereas that of 4-NP ranged from 5.1 ± 2.6 to 12.2 ± 3.6 μg kg^–1. Concentrations of 17-β-estradiol in vegetables and fruits ranged from 1.3 ± 0.4 to 2.2 ± 1.0 μg kg^–1 except those in tomato and strawberry, in which no 17-β-estradiol was detected. The estimated daily intake of 17-β-estradiol was beyond the recommended acceptable daily intake (ADI) for children as recommended by the Joint FAO/WHO Expert Committee on Food Additives (JECFA)

Nutrients and Nonessential Elements in Soil after 11 Years of Wastewater Irrigation

Irrigation of citrus (Citrus aurantium L. x Citrus paradise Macf.) with urban reclaimed wastewater (RWW) can be economical and conserve fresh water. However, concerns remain regarding its deleterious effects on soil quality. We investigated the ionic speciation (ISP) of RWW and potential impacts of 11 yr of irrigation with RWW on soil quality, compared with well-water (WW) irrigation. Most of nutrients (similar to 53-99%) in RWW are free ionic species and readily available for plant uptake, such as: NH4+, NO3-, K+, Ca2+, Mg2+, SO42-, H3BO3, Cl-, Fe2+, Mn2+, Zn2+, Co2+, and Ni2+, whereas more than about 80% of Cu, Cr, Pb, and Al are complexed with CO3-, OH-, and/or organic matter. The RWW irrigation increased the availability and total concentrations of nutrients and nonessential elements, and soil salinity and sodicity by two to three times compared with WW-irrigated soils. Although RWW irrigation changed many soil parameters, no difference in citrus yield was observed. The risk of negative impacts from RWW irrigation on soil quality appears to be minimal because of: (i) adequate quality of RWW, according to USEPA limits; (ii) low concentrations of metals in soil after 11 yr of irrigation with RWW; and (iii) rapid leaching of salts in RWW-irrigated soil during the rainy season.FAPESP (Sao Paulo Research Foundation) [06/56419-6]Sao Paulo Research Foundation (FAPESP)University of FloridaUniversity of Florid