The input reduction principle of agroecology is wrong when it comes to mineral fertilizer use in sub-Saharan Africa

Gatien Falconnier Marc Corbeels Frédéric Baudron Antoine Couëdel leonard rusinamhodzi bernard vanlauwe Ken Giller (2023, [Artículo])

Can farmers in sub-Saharan Africa (SSA) boost crop yields and improve food availability without using more mineral fertilizer? This question has been at the center of lively debates among the civil society, policy-makers, and in academic editorials. Proponents of the “yes” answer have put forward the “input reduction” principle of agroecology, i.e. by relying on agrobiodiversity, recycling and better efficiency, agroecological practices such as the use of legumes and manure can increase crop productivity without the need for more mineral fertilizer. We reviewed decades of scientific literature on nutrient balances in SSA, biological nitrogen fixation of tropical legumes, manure production and use in smallholder farming systems, and the environmental impact of mineral fertilizer. Our analyses show that more mineral fertilizer is needed in SSA for five reasons: (i) the starting point in SSA is that agricultural production is “agroecological” by default, that is, very low mineral fertilizer use, widespread mixed crop-livestock systems and large crop diversity including legumes, but leading to poor soil fertility as a result of widespread soil nutrient mining, (ii) the nitrogen needs of crops cannot be adequately met solely through biological nitrogen fixation by legumes and recycling of animal manure, (iii) other nutrients like phosphorus and potassium need to be replaced continuously, (iv) mineral fertilizers, if used appropriately, cause little harm to the environment, and (v) reducing the use of mineral fertilizers would hamper productivity gains and contribute indirectly to agricultural expansion and to deforestation. Yet, the agroecological principles directly related to soil fertility—recycling, efficiency, diversity—remain key in improving soil health and nutrient-use efficiency, and are critical to sustaining crop productivity in the long run. We argue for a nuanced position that acknowledges the critical need for more mineral fertilizers in SSA, in combination with the use of agroecological practices and adequate policy support.

Manure Crop Yields Smallholder Farming Systems Environmental Hazards CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA BIOLOGICAL NITROGEN FIXATION LEGUMES NUTRIENT BALANCE SOIL FERTILITY AGROECOLOGY YIELD INCREASES LITERATURE REVIEWS

Enhancing maize's nitrogen-fixing potential through ZmSBT3, a gene suppressing mucilage secretion

jiafa chen XUECAI ZHANG Jianyu Wu (2023, [Artículo])

Aerial Roots ZmSBT3 Diazotroph CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE ADVENTITIOUS ROOTS MUCILAGES NITROGEN FIXATION GENOME-WIDE ASSOCIATION STUDIES GENE CLONING NITROGEN FIXING BACTERIA

Targeted nitrogen management to increase cereal production while reducing nitrogen consumption in India

Tek Sapkota Sieglinde Snapp (2022, [Objeto de congreso])

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CEREAL PRODUCTS PRODUCTION SYSTEMS CEREALS NITROGEN RICE WHEAT MAIZE

Optimization of N dose in rice under conservation agriculture with sub-surface drip fertigation

C.M. Parihar Hari Sankar Nayak Renu Pandey Avinash Kumar ML JAT (2021, [Artículo])

Biological Yield Economic N Dose Yield Attributes CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA YIELDS NITROGEN ZERO TILLAGE DIRECT SOWING RICE

Remoción de macronutrientes en el tratamiento de aguas residuales porcícolas

Macronutrients removal in the treatment of swine wastewater

VIOLETA ERENDIRA ESCALANTE ESTRADA MARCO ANTONIO GARZON ZUÑIGA SERGIO VALLE CERVANTES (2012, [Artículo])

Se presentan los resultados de una comparación realizada entre los procesos biológicos más utilizados para el tratamiento de efluentes porcícolas. Estos procesos son: digestores anaerobios, reactor anaerobio de flujo ascendentes, filtros anaerobios, reactor secuencial en lote, sistemas lagunares y biofiltros. Se concluye que una buena opción de tratamiento podría ser un sistema combinado de filtros sumergidos anaerobios con filtro percolador aireado, ya que los filtros anaerobios requieren un menor tiempo de retención hidráulico para la reducción de la materia orgánica y por otra parte, los biofiltros aerados pueden alcanzar eficiencias de remoción de nitrógeno mayores a las de otros sistemas (lagunas, variantes de lodos activados, etcétera). Sin embargo, aunque existen algunos estudios sobre el seguimiento de los mecanismos para la remoción de nitrógeno en biofiltros, se requiere realizar estudios adicionales al respecto. Se propone que una posible estrategia sería estudiando el efecto de la relación C/N y de la tasa aireación en estos sistemas de tratamiento.

Efluentes industriales Porcinos Tratamiento de aguas residuales Nitrógeno INGENIERÍA Y TECNOLOGÍA

Reactor con biomasa inmovilizada (BIOSTAR): alternativa para remoción biológica de nitrógeno

Petia Mijaylova Nacheva GABRIELA ELEONORA MOELLER CHAVEZ gabriela mantilla morales (2012, [Documento de trabajo])

En la Subcoordinación de Tratamiento de Aguas Residuales del IMTA se desarrolló un reactor biológico denominado BIOSTAR el cual ya está comercializado para el tratamiento descentralizado de aguas residuales de pequeñas poblaciones, fraccionamientos habitacionales, zonas residenciales, casas-habitación, hoteles, centros comerciales, edificios públicos, centros comerciales o recreativos. Se puede obtener agua con calidad adecuada para su desinfección con luz UV y posterior reutilización en servicios al público, cumpliendo con los límites máximos permisibles que para esto se establecen en la NOM-002-SEMARNAT/1997, así como con los límites para descarga a cuerpos receptores según la NOM-001-SEMARNAT/1996. El principal objetivo de tratamiento con el BIOSTAR es la remoción de la materia orgánica en el agua residual.

Tratamiento de aguas residuales Filtros biológicos Biomasa Nitrógeno INGENIERÍA Y TECNOLOGÍA

Classification of Cucumber Leaves Based on Nitrogen Content Using the Hyperspectral Imaging Technique and Majority Voting.

Sajad Sabzi Razieh Pourdarbani Mohammad Hossein Rohban Alejandro Fuentes_Penna José Luis Hernández-Hernández Mario Hernández Hernández (2021, [Artículo])

Improper usage of nitrogen in cucumber cultivation causes nitrate accumulation in the fruit and results in food poisoning in humans; therefore, mandatory evaluation of food products becomes inevitable. Hyperspectral imaging has a very good ability to evaluate the quality of fruits and vegetables in a non-destructive manner. The goal of the present paper was to identify excess nitrogen in cucumber plants. To obtain a reliable result, the majority voting method was used, which takes into account the unanimity of five classifiers, namely, the hybrid artificial neural network¿imperialism competitive algorithm (ANN-ICA), the hybrid artificial neural network¿harmonic search (ANN-HS) algorithm, linear discrimination analysis (LDA), the radial basis function network (RBF), and the Knearest- neighborhood (KNN). The wavelengths of 723, 781, and 901 nm were determined as optimal wavelengths using the hybrid artificial neural network¿biogeography-based optimization (ANNBBO) algorithm, and the performance of classifiers was investigated using the optimal spectrum. The results of a t-test showed that there was no significant difference in the precision of the algorithm when using the optimal wavelengths and wavelengths of the whole range. The correct classification rate of the classifiers ANN-ICA, ANN-HS, LDA, RBF, and KNN were 96.14%, 96.11%, 95.73%, 64.03%, and 95.24%, respectively. The correct classification rate of majority voting (MV) was 95.55% for test data in 200 iterations, which indicates the system was successful in distinguishing nitrogen-rich leaves from leaves with a standard content of nitrogen.

artificial neural network cucumber hyperspectral imaging majority voting nitrogen INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LOS ALIMENTOS

Mejoramiento del grado de uso del nitrógeno en maíz mediante técnicas parcelarias de riego por superficie

Improving the usage level of nitrogen in maize, through surface irrigation plot techniques

JAIME MACIAS CERVANTES JESUS DEL ROSARIO RUELAS ISLAS PABLO PRECIADO RANGEL WALDO OJEDA BUSTAMANTE MARCO ANTONIO INZUNZA IBARRA JOSE ALFREDO SAMANIEGO GAXIOLA (2015, [Artículo])

El maíz es uno de los principales cultivos sembrados en el estado de Sinaloa; sin embargo, en esta región la aplicación de riegos se realiza sin considerar las características físicas del suelo incrementando las pérdidas de agua y fertilizantes. Es importante desarrollar tecnologías que permitan optimizar el uso de insumos (agua, fertilizantes, pesticidas) incrementando el potencial productivo de los cultivos y reduciendo los costos de producción, por tal motivo, se desarrollaron una serie de experimentos durante los ciclos otoño-invierno 2006-2007 y 2011-2012 en el norte de Sinaloa, México, con el propósito de conocer el efecto del riego por gravedad por diferentes técnicas en la eficiencia de uso del nitrógeno (N) en el cultivo de maíz.

Riego de baja presión Riego de superficie Nitrógeno Cultivos alimenticios Maíz INGENIERÍA Y TECNOLOGÍA

GWAS identifies genetic loci underlying nitrogen responsiveness in the climate resilient C4 model Setaria italica (L.)

Tirthankar Bandyopadhyay Stéphanie M. Swarbreck Vandana Jaiswal Rajeev Gupta Alison Bentley Manoj Prasad (2022, [Artículo])

C4 Model Crop Climate Resilience CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CLIMATE RESILIENCE FOOD SECURITY GENE EXPRESSION NITROGEN

Enhancing maize yield in a conservation agriculture-based maize (Zea mays)- wheat (Triticum aestivum) system through efficient nitrogen management

C.M. Parihar Hari Sankar Nayak Dipaka Ranjan Sena Shankar Lal Jat Mahesh Gathala Upendra Singh (2023, [Artículo])

This study evaluated the impact of contrasting tillage and nitrogen management options on the growth, yield attributes, and yield of maize (Zea mays L.) in a conservation agriculture (CA)-based maize-wheat (Triticum aestivum L.) system. The field experiment was conducted during the rainy (kharif) seasons of 2020 and 2021 at the research farm of ICAR-Indian Agricultural Research Institute (IARI), New Delhi. The experiment was conducted in a split plot design with three tillage practices [conventional tillage with residue (CT), zero tillage with residue (ZT) and permanent beds with residue (PB)] as main plot treatments and in sub-plots five nitrogen management options [Control (without N fertilization), recommended dose of N @150 kg N/ha, Green Seeker-GS based application of split applied N, N applied as basal through urea super granules-USG + GS based application and 100% basal application of slow release fertilizer (SRF) @150 kg N/ha] with three replications. Results showed that both tillage and nitrogen management options had a significant impact on maize growth, yield attributes, and yield in both seasons. However, time to anthesis and physiological maturity were not significantly affected. Yield attributes were highest in the permanent beds and zero tillage plots, with similar numbers of grains per cob (486.1 and 468.6). The highest leaf area index (LAI) at 60 DAP was observed in PB (5.79), followed by ZT(5.68) and the lowest was recorded in CT (5.25) plots. The highest grain yield (2-year mean basis) was recorded with permanent beds plots (5516 kg/ha), while the lowest

was observed with conventional tillage (4931 kg/ha). Therefore, the study highlights the importance of CA practices for improving maize growth and yield, and suggests that farmers can achieve better results through the adoption of CA-based permanent beds and use of USG as nitrogen management option.

Green Seeker Urea Super Granules CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE UREA YIELDS ZERO TILLAGE NITROGEN