Abstract In traditional row and strip cowpea-sorghum intercropping systems, cowpea forage yield reduces significantly due to intense competition and dominance of sorghum in acquiring growth resources. This field study evaluated novel mixed strip intercropping systems of forage cowpea and sorghum having different number of crops rows arranged under different spatial arrangements. Cowpea was intercropped with sorghum in 8, 12 and 16 rows strips with row-row spacing of 30, 45 and 60 cm. In each strip, equal number of rows of cowpea and sorghum were maintained. Factorial arrangement of randomized complete block design with three replicates was used to execute the field trials during summer seasons of 2013 and 2014. Strips having 12 rows and 60 cm row-row spacing positively affected all agronomic variables of cowpea which led to maximum forage yield (22.2 and 23.7 t ha-1 during 2013 and 2014 respectively) and dry matter biomass (6.63 and 6.94 t ha-1 during 2013 and 2014 respectively). In contrast, 8-rows strips having line spacing of 30 cm outperformed other intercropping systems by yielding the maximum herbage yield and dry matter biomass of sorghum. The intercropping system comprising of 12-rows strips with 60 cm row-row spacing remained superior in recording the maximum crude protein, fats and total ash along with the minimum fiber content of cowpea. In addition, this intercropping system under rest of spatial arrangements also remained unmatched, while 16-rows strips under all planting geometries remained inferior to other intercropping systems. Thus, cowpea intercropping with sorghum in 12-rows strips having 60 cm spacing offers biologically viable solution to improve biomass and forage quality of cowpea in intercropping with sorghum.

Resumen En los sistemas tradicionales de cultivo intercalado de frijol caupí y sorgo en franjas y filas, el rendimiento de forraje del frijol caupí se reduce significativamente debido a la intensa competencia y al dominio del sorgo en la adquisición de recursos para el cultivo. Este estudio de campo evaluó novedosos sistemas de cultivo intercalado en franjas mixtas de frijol caupí forrajero y sorgo con diferente número de filas de cultivo en diferentes disposiciones espaciales. El frijol caupí se intercaló con el sorgo en franjas de 8, 12 y 16 filas con un espaciamiento de 30, 45 y 60 cm entre las filas. En cada franja se mantuvo igual número de filas de frijol caupí y sorgo. Para la ejecución de los ensayos de campo durante las temporadas de verano de 2013 y 2014 se utilizó un diseño factorial en bloques completos aleatorizados con tres repeticiones. Las franjas con 12 filas y un espaciamiento de 60 cm entre las filas afectaron positivamente a todas las variables agronómicas del frijol caupí que condujeron al máximo rendimiento forrajero (22.2 y 23.7 t/ha en 2013 y 2014, respectivamente) y de biomasa de materia seca (6.63 y 6.94 t/ha en 2013 y 2014, respectivamente). En cambio, las franjas de 8 filas con un espaciamiento de 30 cm superaron a otros sistemas de cultivo intercalado al obtener el rendimiento máximo de hierba y de biomasa de materia seca del sorgo. El sistema de cultivo intercalado compuesto por franjas de 12 filas con un espaciamiento de 60 cm entre las filas siguió siendo superior, al registrar el contenido máximo de proteína bruta, grasas y cenizas junto con el mínimo contenido de fibra de frijol caupí. Además, este sistema de cultivo intercalado bajo el resto de las disposiciones espaciales también permaneció incomparable, mientras que las franjas de 16 filas bajo todas las geometrías de siembra permanecieron inferiores a otros sistemas de cultivo intercalado. Por lo tanto, el cultivo intercalado de frijol caupí con sorgo en franjas de 12 filas con un espaciado de 60 cm ofrece una solución biológicamente viable para mejorar la biomasa y la calidad del forraje del caupí en cultivo intercalado con sorgo.

Abstract Organic manures are more preferred and environmentally friendly than chemical fertilizers for minimally contaminating soil, water and environmental resources, but the determination of right source of organic manures continues to remain an unexplored aspect. Considering the important issue, a multi-year field trial was carried out to determine the response of forage soybean to four sources of nutrients such as chemical fertilizers (IF), poultry litter (PL), bovine’s farm yard slurry (BFYS) and sewage sludge (SS) and their seven binary combinations (PL+BFYS, PL+SS, PL+IF, BFYS+SS, BFYS+IF, SS+IF and PL+BFYS+SS). Supplementation of organic manures with mineral fertilizers remained superior to their sole application, particularly BFYS + IF was found significantly (p≤0.05) superior for yielding the highest fresh biomass (23.9, 26.4 and 25.7 t ha–1) with improved nutritional quality. The same combination of integrated fertilizer management also recorded higher sustainability as per sustainable forage yield index along with the highest net income and the benefit-cost ratio. PL and SS applied in conjunction with IF performed better than sole or binary application of organic manures. Therefore, BFYS + IF may be recommended for adoption to produce comparable forage yield and nutritional quality of soybean along with reducing dependency on chemical fertilizers.

ABSTRACT Cereal-legumes intercropping is among the most economical and effective agronomic strategies to boost forage biomass production, nutritional quality and monetary returns. This review synthesizes the research findings on how intercropping affects productivity, quality, competitiveness and economic viability of sorghum-legumes mixed, row and strip intercropping systems under varied pedo-climatic conditions. Though component crops show yield reductions in row (additive and row-replacement series), mixed (seed blended crops) and strip intercropping systems, in general overall productivity per unit land area increases to a great extent. The significantly higher resource capturing with better utilization efficacy by intercrops in temporal and spatial dimensions helps explain their greater productivity. In addition, forage intercrops result in improved nutritional quality as legumes contain protein in double quantity than cereals. Cereal-legumes intercropping systems yield higher quantities of lush green forage with improved quality traits, which ultimately increase monetary benefits. Furthermore, legumes inclusion as an intercrop with cereals has the potential to serve as a nitrogen-saving strategy due to the biological nitrogen fixation (BNF) process. Moreover, cereal-legume intercropping systems are effective in reducing weed infestations and soil erosion by providing extended soil cover, as well as in increasing water use efficiency and improving soil fertility. However, despite a significant increase in overall productivity, component crops suffer yield losses in intercropping systems owing to competition for the finite divisible pool of growth resources. Thus, there is a dire need to optimize spatial and temporal arrangements in sorghum-legumes intercropping systems to achieve maximum productivity and economic returns.

ABSTRACT Harvesting time and type of accession of forage legumes are important factors to determine their performance as companion crops for cereals. The objective of this multi-year field trial was to evaluate different harvesting times of forage cluster bean accessions sown as companion crops with forage sorghum under irrigated conditions. Treatments included two accessions (BR-90 and BR-99) and four harvesting times (pre-flowering, complete flowering, 50 and 100% pod formation). The BR-99 accession harvested at 100% pod formation had greater performance with respect to green forage yield (20.42 t·ha-1) and dry matter biomass (5.80 t·ha-1) and it was statistically at par within the same accession harvested at 50% pod formation. The highest quality forage with the maximum crude protein and ether extractable fat and lowest crude fiber was recorded by BR-99 harvested at 50% pod formation, while BR-90 did not perform at par at all harvesting times. Harvesting of BR-99 at 100% pod formation also resulted in the highest net income along with the benefit-cost ratio. The harvesting of BR-99 at 50 and 100% pod formation resulted in non-significant differences of forage yields and economic returns, however, the quality of cluster bean forage deteriorated at 100% pod formation thus harvesting at 50% pod formation would be preferred.

ABSTRACT Soybean suffers a serious blow to forage yield and quality while in intercropping with cereal forages like sorghum. The aim of this field investigation was to optimize planting time and spatial arrangement for boosting yield, quality and profitability of intercropped soybean. Treatments included soybean sown 20 days before and after sorghum under different spatial arrangements (3-1, 1-3, 2-3, 3-2 and 3-3 row proportions). The factorial arrangement was used to employ randomized complete block design (RCBD) for experimental execution with four replicates. Soybean sown 20 days prior to sorghum in 2-3 row replacement series was effective in yielding the highest yield attributes of soybean, which led to the highest green forage yield and dry matter biomass. The same intercropping system proved to be superior in generating the highest net income and benefit-cost ratio (BCR) (4.31). Correlation analysis revealed a positive correlation between agronomic variables under study and forage yield of soybean. Better quality forage with significantly higher crude protein, ether extractable fat and ash along with the lowest crude fiber content was given by soybean planted 20 days before sorghum in 3-2 row proportion. Soybean sown 20 days after sorghum under all spatial arrangements did not perform at par with soybean sown 20 days before sorghum. Thus, in order to avoid the drastic effects of sorghum on soybean forage yield and quality in soybean-sorghum intercropping systems, deferred sowing of sorghum might be considered keeping in view the availability of irrigation water and available time with respect of next crop.

Abstract: Sustainable production of quality forages in sufficient quantities constitutes one of the biggest challenges for profitable dairy farming. Forage legumes including cowpea offer a feasible solution to meet this task but planting geometry for spreading and erect types of varieties needs to be optimized. Two cowpea varieties (P-518 and Rawan-2003) were sown to different row spacing (30, 45 and 60 cm), while broadcasted crops were kept for comparison. Factorial arrangement of randomized complete block design (RCBD) was employed to carry out the field trial with four replicates. Dry matter biomass, quality variables, net income and benefit-cost ratio were taken as experimental variables. Rawan-2003 (spreading type) sown at 45 cm spaced rows gave significantly (P≤0.01) higher dry matter biomass (8.26 and 9.03 t ha-1 in 2013 and 2014, respectively) along with significantly (P≤0.05) improved forage quality (especially higher crude protein and lower crude fiber contents). The same variety and spatial arrangement resulted in the highest net income and benefit-cost ratio (BCR) (4.66 and 4.85 in 2013 and 2014 respectively). P-518 (erect type) gave better results with closer inter-row spacing (30 cm spaced rows), while broadcasting of both cowpea varieties proved to be inferior to all other spatial arrangements.

Resumen: La producción sustentable de forrajes de calidad en cantidades suficientes constituye uno de los mayores retos para la ganadería lechera rentable. Leguminosas forrajeras incluyendo el frijol caupí ofrecen una solución factible para cumplir con esta tarea, pero se deben optimizar los arreglos de la siembra y la selección de variedades rastreras y erectas. Se sembraron dos variedades de frijol (P-518 y Rawan-2003) con diferente espaciamiento entre surcos (30, 45 y 60 cm), mientras que cultivos ya establecidos se mantuvieron para la comparación. Se utilizó un arreglo factorial de diseño de bloques completos al azar con cuatro repeticiones para llevar a cabo el ensayo de campo. Biomasa de materia seca, las variables de calidad, ingreso neto y relación beneficio-costo se tomaron como variables experimentales. Rawan-2003 (tipo rastrero) sembrado en hileras de 45 cm de espaciado dio significativamente (P≤0.01), mayor biomasa de materia seca (8.26 y 9,03 t ha-1 en 2013 y 2014, respectivamente) y mejoró significativamente (P≤0.05) la calidad del forraje (mayor proteína cruda y menor contenido de fibra cruda). La misma variedad y arreglo espacial resultaron en el mayor ingreso neto y relación beneficio-costo (BCR) (4.66 y 4.85 en 2013 y 2014 respectivamente). El tipo erguido P-518 dio mejores resultados con espaciamiento entre surcos más cercanos (30 cm), mientras que las variedades de frijol testigo demostraron ser inferiores a todos los otros arreglos espaciales.