Tillage and nutrient management influence net global warming potential and greenhouse gas intensity in soybean-wheat cropping system

Conservation tillage has proven advantageous in improving soil health and productivity. However, the greenhouse gases (GHGs) emission and intensity from different conservation tillage and nutrient management systems under Indian conditions are less understood. Therefore, here, we compared the effect of tillage and nutrient management on GHGs emissions, net global warming potential (NGWP), and greenhouse gas intensity (GHGI) from a field experiment under five years in a soybean-wheat cropping system in the Vertisols. The tillage treatments comprised of reduced tillage (RT) and no tillage (NT). The three nutrient management treatments included application of 100% NPK (T1), 100% NPK + 1.0 Mg FYM-C ha-1 (T2), 100% NPK +2.0 Mg FYM-C ha-1 (T3). The results showed significantly higher SOC sequestration under NT (1388 kg ha-1 yr-1) followed byRT (1134 kg ha-1 yr-1) with application of FYM (2.0 Mg C ha-1) (T3) every year. Across tillage, integrated nutrient management(T2 and T3) lowered NGWP and GHGI compared to NPK (T1). The GHGI of NT system was less by 33% compared to RT. The results suggest that GHGs mitigation and sustained food production in the soybean-wheat system can be achieved in NT and RT with integrated use of organic and inorganic fertilizer as the major component of nutrient management.

Estimación de erosión potencial bajo dos sistemas de corte de caña panelera utilizando la ecuación universal de pérdida de suelos / Estimation of potential erosion under two sugarcane cutting systems using the universal soil loss equation

RESUMEN Con el fin de comparar las pérdidas de suelo en dos sistemas de corte tradicionalmente utilizados en el cultivo de caña de azúcar para la producción de panela, se llevó a cabo un estudio, en el que se realizaron mediciones en campo, utilizando un simulador de lluvia y parcelas de escorrentía, en un vertisol del municipio de Quebradanegra, Cundinamarca, en donde se presentan, simultáneamente, los dos tipos de corte: parejo (tipo de corte en el que se cosecha todo a la vez, al tener una madurez homogénea en el cultivo) y entresaque (sistema en el cual no hay madurez homogénea, por lo que se corta solo un porcentaje de las plantas a la vez). Para estimar las pérdidas de suelo potenciales asociadas a ambos sistemas de corte, se utilizó la Ecuación Universal de Pérdida de Suelos (USLE), obteniendo un factor medio C, asociado al tipo de corte, utilizando los datos determinados en campo y la erosividad de las intensidades de precipitación simuladas. Finalmente, se determinó la erosión potencial anual, bajo los dos sistemas de corte, donde se observó que el sistema de corte por parejo presenta un valor 2,2 veces mayor que el sistema de corte por entresaque. Por otra parte, al comparar las pérdidas potenciales de suelo con un lote recién preparado y sembrado, sin cobertura vegetal, se evidencia la capacidad del cultivo de caña panelera para brindar protección al suelo, presentando una erosión potencial 9 veces menor, en el caso del corte por parejo, con respecto a una condición de suelo sin cobertura vegetal.

ABSTRACT In order to compare soil losses in two cutting systems traditionally used in the cultivation of sugar cane for the production of panela, a study was carried out in which measurements were made in the field using a rainfall simulator and runoff plots in a vertisol of the municipality of Quebradanegra, Cundinamarca, where both types of cut are presented simultaneously: the cut-off system, in which everything is harvested at once having a homogeneous maturity in the crop and the thinning cut system, in which have an inhomogeneous maturity so that only a percentage of the plants is cut at the same time. To estimate the potential soil losses associated with both cutting systems, the Universal Soil Loss Equation (USLE) was used to obtain a mean C factor associated with the type of cut, using the data determined in the field and the erosivity of simulated rainfall intensities. Finally, the anual potential losses of soil was determined under the two cutting systems, where it was observed that the cut-off system has an annual potential erosion 2.2 times greater than the thinning cuy system. On the other hand, when comparing the potential losses of soil with a newly prepared and planted lot, without plant cover, the capacity of the sugarcane cane crop is demonstrated to offer a protection to the soil, presenting a potential erosion 9 times smaller, in the case of the cut-off system, with respect to a soil condition without plant cover.

Evaluations of soil Fertility Status of Available Major Nutrients (N,P & K) and Micro Nutrients (Fe, Mn, Cu & Zn) in Vertisol of Kabeerdham District of Chhattisgarh, India.

Grid based (GPS) surface (0-15 cm) soil samples by systematic survey were collected from 4 blocks, 84 selected villages in Kabeerdham district were 297samples identified from Vertisol. These soil samples were analyzed for N,P and K and Fe, Mn, Cu and Zn andcategorized as low medium and high as per criteria fallowed in the soil testing laboratory. Based upon the coefficient of correlation between macronutrients& micronutrient and soil properties, a significant and positive correlations observed was between soil pH and available N, P and K. Electrical conductivity exhibited significant and positive relationship with available N, P, K and organic C showed significant and positive correlation with available N and K.

Population Dynamics and Diversity of Endophytic Bacteria Associated with Soybean (Glycine max (L) Merril).

Aim: Endophytic bacterial population and their diversity in soybean were investigated. Study Design: Endophytic population was assessed during different growth stages of soybean (CV JS 335) viz., vegetative and reproductive stages. Place and Duration of Study: Microbiology Research Laboratory, Department of Microbiology, R. A. Mahavidyalaya, Washim (MS), India, during the cultivation period of June-December 2010. Methodology: Healthy plants of soybean were screened from the different locations of Washim district (M. S., India). Samples represent each growth stage viz., vegetative (V1- V5) and reproductive (R1-R8) were collected. Population densities were expressed as log10 colony forming units (CFU) g-1 fresh weight. The isolates were identified to genus level according to Bergey’s Manual of Determinative Bacteriology on the basis morphological, cultural and biochemical characteristics. Results: The maximum endophytic population was recorded for vegetative stage at V5 and V4 (5.74 and 5.01 log10 CFU g-1 fresh weight) and for reproductive stage at R2, R1 and R3 (5.84, 5.80 and 5.74 log10 CFU g-1 fresh weight). A total of 572 (35.50 %) from vegetative growth stages and 1039 (64.50 %) from reproductive growth stages bacterial isolates were obtained. The endophytic isolates were identified as members belonging to the genera Pseudomonas, Bacillus, Enterobacter, Klebsiella, Acetobacter Burkholderia, Rhizobium and Xanthomonas. Conclusion: As soybean development progresses endophytic population increased. At maturity, the high population density was observed and thereafter the population declined.

Fertirrigación con diferentes formas de nitrógeno en el cultivo de tomate en un suelo arcilloso / Tomato crop fertigation with different nitrogen form in clayed soil / Fertirrigação com diferentes formas de nitrogênio no cultivo de tomate em um solo argiloso

Se estudió el efecto de nitrógeno nítrico, amoniacal y ureico, suministrados en distintas etapas de desarrollo del cultivo de tomate, sobre el rendimiento y la calidad de fruto. El trabajo se realizó en campo bajo riego por goteo, en un suelo vertisol pélico y clima cálido y semiárido. Tres tratamientos de fertilización (T1, T2 y testigo) fueron distribuidos en un diseño de bloques completos al azar con tres repeticiones. T1 y T2 se fertilizaron con 250-50-190kg·ha-1 de N, P y K, respectivamente; en estos el N se suministró en diferentes proporciones de N-ureico, N-amoniacal y N-nítrico, en distintas etapas de desarrollo del cultivo; el T3 se aplicó como los productores del Valle de Culiacán, Sinaloa, México (450-118-413kg·ha-1 de N-P-K), con 75% del N como nitrato. La concentración de N-NO3 en el extracto celular de peciolos en los T1 y T2 fluctuó de 500 a 1360ppm, y en T3 fue de 300-1175ppm. Estos valores estuvieron relacionados con la dosis de N total suministrado pero no con la proporción de NH4/NO3 aplicada, y tampoco influyeron en la producción de fruto de exportación. La producción de fruto fue estadísticamente igual en las dosis de fertilización alta y moderada, con un ahorro del 75% de N-nítrico. En calidad poscosecha de frutos, la fertilización reducida y la aplicación de N-ureico y N-amoniacal en altas proporciones no afectó la firmeza, ºBrix ni la pérdida de peso de los frutos.

The effect of nitrogen form (urea, nitrate and ammonium) provided at various stages of development of the tomato crop on the yield and quality of fruit was studied. The work was conducted under field conditions in a pellustert soil, drip irrigation and a warm and semi-arid climate. Three fertilization treatments (T1, T2 and control) were arranged in a randomized complete-block design with three replicates. T1 and T2 were fertilized with 250-50-190kg·ha-1 N, P and K, respectively; which N was supplied in different ratios of ureic-N, ammonium-N and nitric-N along growing tomato plants; T3 was provided in a similar way as is generally employed by the tomato producers in the Culiacan Valley, Sinaloa, Mexico (450-118-413kg·ha-1 N-P-K), with 75% of N in nitrate form. The concentration of N-NO-3 in the petiole cell extract in T1 and T2 ranged from 500 to 1360ppm, and in the control it was 300-1175ppm. These values were related with the total N doses supplied but not with the ratio of NH4/NO3 provided, neither influenced on the total amount of exportation fruit. The fruit production was statistically similar in the high and moderated fertilizer doses with a fertilizer savings of 75% of nitrate N. With respect to the post-harvest quality in the tomato fruit, moderated fertilization associated with high application of ureic-N and ammonium-N did not affect the fruit firmness, ºBrix or the weight loss in the fruit.

Estudou-se o efeito do nitrogênio nítrico, amoniacal e uréico, subministrados em distintas etapas de desenvolvimento do cultivo de tomate, sobre o rendimento e a qualidade do fruto. O trabalho se realizou no campo sob irrigação por gotejamento, em um solo vertisol pélico e clima cálido e semi-árido. Três tratamentos de fertilização (T1, T2 e testemunho) foram distribuídos em um desenho de blocos completos aleatório com três repetições. T1 e T2 se fertilizaram com 250-50-190kg•ha-1 de N, P e K, respectivamente; em estes o N se subministrou em diferentes proporções de N-uréico, N-amoniacal e N-nítrico, em distintas etapas de desenvolvimento do cultivo; o T3 se aplicou como os produtores do Vale de Culiacán, Sinaloa, México (450-118-413kg•ha-1 de N-P-K), com 75% do N como nitrato. A concentração de N-NO3 no extrato celular de pecíolos nos T1 e T2 flutuou de 500 a 1360ppm, e em T3 foi de 300-1175ppm. Estes valores estiveram relacionados com a dose de N total subministrado, mas não com a proporção de NH4/NO3 aplicada, e tampouco influíram na produção do fruto de exportação. A produção do fruto foi estatisticamente igual nas doses de fertilização alta e moderada, poupando 75% de N-nítrico. Em qualidade pos-colheita de frutos, a fertilização reduzida e a aplicação de N-uréico e N-amoniacal em altas proporções não afetou a firmeza, oBrix nem a perda de peso dos frutos.