Crop Arrangement Research Articles

Sobressemeadura de pastos anuais de verão na cultura da soja para suprir a escassez de foragem outonal

ABSTRACT: In integrated crop-livestock systems, overseeding annual summer pastures over grain crops can reduce forage shortages in autumn without altering grain production. This study evaluated the influence of pearl millet (Pennisetumglaucum L.) and sudangrass (Sorghum Sudanese) overseeded on a soybean (Glycine Max) crop or no-tillage seeding after soybean harvest on productive aspects of pasture. The experimental design was a randomized block with treatments in a 2 × 2 factorial arrangement (pearl millet or sudangrass, overseeding in the full seed stage (R6) of soybean crops or seeding them in a no-tillage system after soybean harvest) in two agricultural years. Pasture height, plant stand, tiller density, and forage production were higher in the first crop year. The overseeding strategy resulted in higher pasture height and foraged production in the first crop year and higher pasture utilization for the next two crop years. Under the no-tillage strategy, the plants stand more elevated in the first crop year, resulting in a higher tiller density in the second crop year. Pasture height, utilization period, and forage production did not differ among the forage species. Pearl millet had a more elevated plant stand, while sudangrass had a higher tiller density. Annual summer pasture overseeding of soybean crops increases the pasture utilization period and forage production in autumn.

Sustainability evaluation of contrasting milpa systems in the Yucatán Peninsula, Mexico

AbstractThe milpa agroecosystem is an intercropping of maize, beans, squash and other crops, developed in Mesoamerica, and its adoption is widely variable across climates and regions. An example of particular interest is the Yucatan Peninsula in Mexico, which holds highly diverse milpas, drawing on ancestral Mayan knowledge. Traditional milpas have been described as sustainable resource management models, based on long rotations within a slash-and-burn cycle in forest areas. Nevertheless, due to modernization and intensification processes, new variants of the approach have appeared. The objective of this study was to evaluate the sustainability of three milpa systems (traditional, continuous, and mechanized) in four case studies across the Peninsula, with emphasis on food self-sufficiency, social inclusion and adoption of innovations promoted by a development project. The Framework for the Evaluation of Agroecosystems using Indicators (MESMIS, for its Spanish acronym) was used for its flexible, participatory approach. A common group of indicators was developed despite regional differences between study cases, with a high level of farmer participation throughout the iterative process. The results show lower crop yields in traditional systems, but with lower inputs costs and pesticide use. In contrast, continuous milpas had higher value in terms of crop diversity, food security, social inclusion, and innovation adoption. Mechanized milpas had lower weed control costs. Profitability of cash crops and the proportion of forest were high in all systems. Highly adopted innovations across milpa types and study cases included spatial crop arrangement and the use of residues as mulches. However, most innovations are not adapted to local conditions, and do not address climate change. Further, women and youth participation is low, especially in traditional systems.

Effect of Intercropping and Crop Arrangement on Yield and Yield Components of Late Season Maize and Cowpea in the Upland of Njala Soil Series Southern Sierra Leone

Effect of Intercropping and Crop Arrangement on Yield and Yield Components of Late Season Maize and Cowpea in the Upland of Njala Soil Series Southern Sierra Leone

Research Progress on Soil Carbon Sequestration in Dry Farmland

Dry farming is a kind of agricultural production mode widely existed in the world, and its soil carbon sequestration potential has attracted much attention. The paper discussed the influencing factors, carbon sequestration process and effect of soil carbon sequestration in dryland farmland. It was concluded that protective tillage measures such as application of organic fertilizer, no-tillage, deep tillage and straw returning could increase the carbon sequestration in surface dryland soil, biodegradable film mulching could promote soil organic carbon fixation, and rational arrangement of crops could improve soil carbon sequestration capacity.

Markedly declining reproductive functional diversity of food plants in the world’s largest tropical country despite rapid cropland expansion

Cropland intensification in tropical regions is usually associated with agricultural commodity expansion that penalizes the species diversity and environmental services of natural ecosystems. However, the extent to which cropland expansion affects the reproductive functional diversity of crop arrangements remains poorly investigated. Here we examine the agricultural development of a leading agricultural producer and megadiverse country (Brazil) over the last six decades to understand the effects of agricultural expansion on the reproductive functional diversity of crops, particularly those bearing specialized traits. We used the FAO database, which provides annualized information on crop production from 1961 to 2018. Cultivated species were classified according to their reproductive traits and levels of dependence on biotic pollination, used as indicators of functional diversity. Our results show that cropland areas in Brazil expanded by 201.3% from 1961 to 2018. In particular, pollinator‐dependent crops expanded over this period by 305.2% compared to 125.3% in non-dependent crops. Expansion of monoculture farmland was remarkable, comprising 88% of the entire agricultural cropland acreage in 2018, 45% of which was represented by soybean. Additionally, cropland expansion was related to a reduction in functionally diverse crop species, which was most intense for those with specialized reproductive traits. These results indicate a threat to a diversified food production system and its resilience, given the impacts of cropland expansion on native biodiversity and the reduction in pollination services for many crops. We argue that agroecosystems in Brazil require sustainable, pollinator-friendly agricultural practices to maintain or enhance a nutritionally diversified food production system. Integrated practices that sustain agricultural cropland mosaics characterized by high reproductive functional diversity of the cultivated species can be a nature-based solution to protect natural pollinators and pollination services within a diversified food system.

Choosing the right associated crop species in soybean-based intercropping systems: Using a functional approach to understand crop growth dynamics

Intercropping can contribute to increased crop production and stabilization while reducing biotic stress pressure such as that from weeds. In soybean-based intercropping systems, biomass production of the associated crop is a key performance trait for soybean grain production and weed control services. In some situations, spatial arrangement of crops changes the outcome of the intercropping system considered. Lastly, while trait-based approaches are promising for intercrops design, work remains to associate plant functional traits to crop performances. How are plants growth dynamics affected by the associated crop species and spatial arrangement in soybean-based intercrops? Can plant functional traits be related to the grow dynamics parameters? The growth dynamics of soybean, associated crop species and weeds were characterized in eight soybean-based intercropping systems differing in associated species (buckwheat, lentil, sorghum and sunflower) and spatial arrangement (alternate-row or within-row combinations). Leaf traits and plant height were measured for the four associated crops and were related to growth dynamics parameters. Biomass accumulation of the associated crop species was determinant in explaining that of weeds and soybean and thus intercrop performances. Fast and high biomass accumulation by the associated specie implied low weed biomass and to a lesser extent, low soybean biomass accumulation. For buckwheat-soybean and sorghum-soybean intercropping systems, spatial separation of crops in different rows increased soybean growth. Plant functional traits (particularly leaf area and maximum height) can provide valuable information on plant growth dynamics. Associated crop species growth dynamics are the main driver of both soybean and weeds biomass accumulation. To a lesser extent, spatial arrangement offers the opportunity to modulate the interspecific competition. Furthermore, some crop functional traits are related to growth dynamic parameters, offering new perspectives for understanding the performances and designing soybean-based intercrops. Our results underline that the use of easily measured functional traits can provide useful information for intercropping systems design, facilitating crop selection. Nonetheless, much work remains to understand functional traits combinations.

PLANT PHYSIOLOGICAL PERFORMANCE AND SEED CHEMICAL COMPOSITION OF SOYBEAN UNDER DIFFERENT SPATIAL ARRANGEMENT

Few studies present interactions among plant physiological and seed chemical composition of soybean cultivates under different arrangements. Therefore, this study seeks to understand this relationship between space occupation and product quality. We grew two soybean cultivars (Tec 7849 Ipro and Monsoy 6972 Ipro) in four different spatial arrangements (50.0 x 7.1; 40.0 x 8.9; 30.0 x 11.9 and 18.9 x 18.9 or 16.2 x 16.2 cm, respectively). During V4 and R2 phenological stages, we analyzed the gas exchange, and at the harvest were composed two different lots: freshly harvested seeds and the seeds subjected to accelerated aging; in both lots, we evaluated germination test, vigor, germination speed index, seedling fresh mass, and the determination of the chemical composition of the seeds. For experiment conducted to analyze physiological parameters we adopted the factorial scheme 2x2x4 (two evaluation periods x two soybean cultivars x four spatial arrangements), and for seed quality and chemical composition, we adopted the factorial scheme 2x4 (two soybean cultivars x four spatial crop arrangements). The vegetative stage was crucial for better gas exchange efficiency, and the spatial arrangements positively influenced the physiological and chemical quality of the seeds for soybean crop, where the fitted arrangement was observed in 40.0 cm between rows and 8.9 cm between plants for the cultivar Tec 7849 Ipro and 50.0 cm between rows and 5.3 cm between plants, for Monsoy 6972 Ipro. Adjusts in spatial arrangements can promote beneficial responses in seed quality.

Effects of Spatial Row Arrangement and Time of Planting Intercrops on Performance of Groundnut (<i>Arachis hypogaea</i> L.) under Maize (<i>Zea mays</i> L.)—Groundnut Intercropping System in Ejura

In monoculture, crop failure due to biotic or abiotic causes can result in partial or total output failure. The yield, socio-economic, and environmental effects of intercropping on the farmer and the environment as a whole have not received much attention. There is a dearth of knowledge on the productivity of maize-groundnut intercrops in Ghana regarding the relative timing of planting and spatial arrangement of component crops. Therefore, the objective of the study was to determine the effects of spatial row arrangement and the time of planting intercrops on the productivity of groundnut under maize-groundnut intercropping. The 5 × 3 factorial field experiment was undertaken at the Miminaso community in the Ejura-Sekyedumase municipality of the Ashanti Region of Ghana during the 2020 cropping seasons. Treatments were evaluated in a Randomized Complete Block Design (RCBD) with three replicates. The levels of row arrangement of intercrops were: one row of maize and one row of groundnut (1M1G), one row of maize and two rows of groundnut (1M2G), two rows of maize and one row of groundnut (2M1G), two rows of maize and two rows of groundnut (2M2G), sole maize and sole groundnut (M/G). The levels of time of introducing groundnut included simultaneous planting of intercrops (0 WAP), planting groundnut one week after planting maize (1 WAP) and planting groundnut two weeks after planting maize (2 WAP). There were significant (P 0.05) treatment interactions for pod and seed yields of groundnut throughout the study. The highest groundnut pod yields of 1815.00 kg/ha and 2359.00 kg/ha were recorded by the 0WAP × 1M2G treatment in the major and minor seasons of 2020, respectively, while the highest groundnut seed yields of 741.00 kg/ha and 726.00 kg/ha were recorded in the major and minor rainy seasons of 2020 by 1WAP × G and 0WAP × G treatments, respectively. The highest seed yields of groundnut (404 kg/ha and 637 kg/ha for major and minor rainy seasons, respectively) were produced by 1WAP × 2M2G.

Integrated management of agronomic practices in the forage cactus: maximising productivity, biological efficiency and economic profitability

Forage cactus cropping systems that include a combination of agricultural practices (cloning, irrigation, mulching and/or intercropping) can increase forage production and economic return in semi-arid environments. This study evaluated the effect on productivity, biological efficiency and economic return of combining different practices with forage cactus cropping systems in the semi-arid region of Brazil. The research was conducted in four experimental areas, in a randomised block design with four replications, and included the following practices: 1) clones – irrigation - cover, 2) different irrigation depths, 3) intercropping - mulching, and 4) different levels of mulch. The treatments in experiment I consisted of three cactus clones (‘Orelha de Elefante Mexicana’—OEM; ‘Miúda’—MIU and ‘IPA-Sertânia’—IPA), two water regimes (rainfed and irrigated), and two levels of mulch (with and without mulch). Experiment II comprised four irrigation depths (0, 40, 80 and 120% of the crop evapotranspiration) and three cactus clones. In experiment III, three crop arrangements (single cactus, cactus intercropped with millet, and single millet) were evaluated under two levels of mulching (with and without mulching). In experiment IV, four levels of mulch were used (0, 5, 10 and 15 Mg ha-1). The total number of cladodes per plant, fresh matter yield (YFM), dry matter yield (YDM), and final plant density were obtained when harvesting. Economic viability was assessed using the profitability index (PI). The rainfed systems showed greater yield. The use of mulch afforded greater productivity. The OEM clone (YFM = 310.76 Mg ha-1 and YDM = 29.87 Mg ha-1) obtained a higher yield than did the IPA and MIU clones. The highest PI values were achieved under the rainfed systems. The MIU and IPA clones exhibited lower PI values. The cactus-millet intercrop achieved the best performance with the use of mulch. Cactus systems of 15.0 Mg ha-1 showed a greater PI value. It was concluded that the integrated management of such practices as intercropping, mulching and the adoption of the OEM clone can increase the supply of forage. These practices can promote the sustainable intensification of forage input in Livestock Production Systems in semi-arid environments.

Intercropping of Cauliflower With Sweet Gourd At Different Plant Population

Intercropping is a popular way to boost crop yield and profitability by maximizing the use of natural and agricultural resources. A study was carried out to establish crop arrangement for sweet gourd and cauliflower intercropping systems. The experiment was carried out during two consecutive years of 2019-20 and 2020-21 to identify the appropriate cauliflower population for intercropping with sweet gourd for increased production and profitability. Seven treatments viz. T1= Sole Sweet gourd (2 m × 2 m), T2=100% Sweet gourd + 3 rows cauliflower 37.5% (60 cm × 50 cm), T3=100% Sweet gourd + 3 rows cauliflower 23% (60 cm × 80 cm), T4=100% Sweet gourd + 4 rows cauliflower 50% (50 cm × 50 cm), T5=100% Sweet gourd + 4 rows cauliflower 31% (50 cm × 80 cm), T6=100% Sweet gourd + 5 rows cauliflower 31% (40 cm × 100 cm) and T7=Sole Cauliflower (50 cm × 50 cm). The maximum sweet gourd equivalent yield (SGEY) 34.83 t ha-1 was obtained from T4. The maximum gross return (Tk. 278640 ha-1), gross margin (Tk. 180384 ha-1), BCR (2.85) and LER (1.40) were also observed from T4 and the lowest in sole cauliflower (T7). The overall results revealed that among the intercrop combinations 100% Sweet gourd+4 rows cauliflower 50% (50 cm × 50 cm) (T4) followed by 100% Sweet gourd + 3 rows cauliflower 37.5% (60 cm × 50 cm) (T2) combinations could be profitable combinations for cauliflower with sweet gourd intercropping system.
 Bangladesh Agron. J. 2022, 25(1): 129-138

Influence of Plant Spacing and Intercropping on the Growht and Septoria Leaf Spot of Tomato (Lycopersicon esculentum Mill)

The influence of plant spacing and intercropping on the growth and septoria leaf spot disease incidence and severity of tomato were studied in Owerri, the south east of Nigeria, in the year 2011.The study was designed as a 4x4 factorial in a Randomized Complete Block Design with three (3) replications. Data on growth parameters and septoria leaf spot disease incidence and severity of tomato were collected and statistically analyzed by using Gensat version 4 analytical software, while the means were separated for difference using Fisher’s Least Significant Difference Protocol. The result showed a significant (P<0.05) reduction of septoria leaf spot disease incidence to 0.00% by intercropping at the distance of 75 x 50 cm under tomato sole cropping arrangement. The intercrop combination of tomato/groundnut/soybean also significantly (P<0.05) reduced septoria leaf spot disease incidence (6.7%) under the spacing of 100 x 75 cm. Intercropping significantly (P<0.05) influenced septoria leaf spot disease severity at 6 weeks of transplanting. Similarly, plant spacing of 75 x 50 cm and under the tomato sole crop arrangement significantly reduced the tomato septoria leaf spot disease severity.

Beneficial and Pest Arthropod Responses to Tillage and Cover Crop Residues in Organic Cucurbits.

Reduced tillage methods such as strip tillage are often combined with cover crop mixtures to provide agronomic benefits which can support crop and soil health. However, reduced tillage and cover crop species/arrangements effects on arthropods is less understood and results of previous studies have varied. In this study, we examined how agriculturally relevant pest and beneficial arthropod species were impacted by tillage and cover crop methods in USDA-certified organic Cucurbita (L.) (Cucurbitales: Cucurbitaceae). Aphididae were the most observed foliar pests and abundance was highest in full tillage treatment plots while foliar herbivores overall, excluding Aphididae, were more abundant in strip tillage treatment plots regardless of cover crop arrangement. Formicidae was also observed more on foliage, flowers, and in pitfall traps in full tillage, similarly to Aphididae. Parasitica were the most observed foliar natural enemies with increased abundance in strip tillage treatments. Activity densities of several epigeal natural enemies were also higher in strip tillage compared to full tillage. No significant effects of tillage and cover crop treatments were observed on flower visitation rates of Eucera pruinosa (Say) (Hymenoptera: Apidae), an important pollinator of Cucurbita, while the highest visitation rates of Apis mellifera (L.) (Hymenoptera: Apidae) and Bombus spp. (Latreille) (Hymenoptera: Apidae) were in strip tillage treatments. These results suggest that reduced tillage methods can support greater abundances of natural enemies and possibly pollinators. This may lead to enhanced biological control and pollination, but impacts may vary for different arthropod species and crops.

Bio-agroeconomic returns in beet-cowpea intercropping by optimization of population densities and spatial arrangements

One of the great challenges of the beet and cowpea cultivation in crop association is to maintain their productivity as that of their sole counterparts in semi-arid environment. In this context, the objective of this work is to assess whether there is bio-agroeconomic return in associations of beet-cowpea by the optimization of population densities and spatial arrangements of the component crops. Experiments were performed in randomised complete block designs with treatments arranged in a 4 × 3 factorial scheme, with four replications. The first factor was the population densities of cowpea (100, 80, 60, and 40% of the recommended population in single crop - RPSC) in association with beet, and the second factor was the spatial arrangements (2:2, 3:3, and 4:4), formed by beet (B) rows alternating with cowpea (C) rows. The competition and agronomic indices evaluated were aggressiveness, competitive ratio, land equivalent ratio, actual yield loss, intercropping advantage and the productive efficiency index. The economic indicators evaluated were gross income, net income, rate of return and profit margin. High agro-economic efficiency can be obtained in the cultivation of beet and cowpea intercropping when well-managing the factors of production, population densities and spatial arrangement of the component crops. The greatest agro-economic return of the cowpea and beet intercropping was obtained in the population densities of 40 and 100% of RPSC for cowpea and beet, respectively. The 2:2 spatial arrangement between beet and cowpea crops was the one with the best productive performance and higher indicators of economic return. The cowpea was the dominant crop while the beet was dominated.

Cropping Patterns of Annual Crops: A Remote Sensing Review

Cropping patterns are defined as the sequence and spatial arrangement of annual crops on a piece of land. Knowledge of cropping patterns is crucial for crop production and land-use intensity. While cropping patterns are related to crop production and land use intensity, they are rarely reported in agricultural statistics, especially those relating to small farms in developing countries. Remote sensing has enabled mapping cropping patterns by monitoring crops’ spatial and temporal dynamics. In this paper, we reviewed remote sensing studies of single, sequential and intercropping patterns of annual crops practiced at local and regional scales. A total of 90 studies were selected from 753 publications based on their cropping pattern types and relevance to the scope of this review. The review found that despite the increase in single cropping pattern studies due to the Sentinel missions, studies on intercropping patterns are rare, suggesting that mapping intercropping is still challenging. More so, microwave remote sensing for mapping intercropping has not been fully explored. Given the complexities in mapping intercropping, our review highlights how less frequently used vegetation indices (VIs) that benefit from red-edge and SWIR spectral bands may improve intercropping mapping.

Impact of Row Ratio and Soil Fertility Management Strategies on Performance of Wheat + Linseed Intercropping System

Background: Intercropping with non-exploited crops is an emerging trend due to their adoptability to changing climatic conditions. There is a considerable scope to bring large area of Bulandshahr region, Uttar Pradesh under linseed through intercropping. The success of intercropping depends mainly on the use compatible crops and their suitable row proportion. The continuous application of inorganic fertilizers even in the balanced form may not sustain soil fertility and productivity. The aim of the present study is to find out the possibility of increasing the production of cereal and oilseeds through intercropping by adopting appropriate spatial arrangement of crops and nutrient management. Methods: A field experiment was conducted at Bulandshahr (U.P.) on sandy loam soil for two consecutive years in split plot design with three replication having five main plot treatments (crop geometry) viz., sole wheat, sole linseed, wheat + linseed (1:1), wheat + linseed (2:1), wheat + linseed (4:1) and four sub plot treatments (fertility levels) viz., 5 t FYM/ha, 50% RD of NPK, 75% RD of NPK and 100% RD of NPK. Result: The results revealed that the plant height at maturity, yields, harvest index, wheat equivalent yield (q/ha), uptake of nitrogen, phosphorus and potassium in grains and straw in wheat were significantly superior in sole wheat followed by wheat + linseed intercropping with 4:1 ratio. Likewise, fertility level of 100% NPK resulted into higher values of above mentioned parameters than their respective counterparts.

Weeding Frequency Effects on Growth and Yield of Dry Bean Intercropped with Sweet Sorghum and Cowpea under a Dryland Area

A better understanding of the dry bean (Phaseolus vulgaris L.) growth and yield response to weed competition under the intercropping system is critical for improving sustainable weed management strategies. A two-year trial was conducted with three types of crop arrangement (sole cropping, inter-row, and intra-row intercropping) combined with weeding frequency (no weeding, weeding over the first 50 days of crop growth, and weed-free). Effects of the treatments were tested on dry bean agronomic indicators in terms of the following: 100-grain weight, dry biomass, grain yield, grains per pod, pods per plant, plant height, number of leaves per plant, and chlorophyll content. The intercropping pattern significantly affected dry bean pods per plant, height, and chlorophyll content, while weeding frequency significantly affected all measured agronomic indicators for dry bean, except for chlorophyll content, during the 2017/18 growing season. The results showed that the significant measured agronomic indicators were the lowest under no weed control; however, they increased as weeding frequency increased. The 2018/19 growing season followed a similar trend; however, the interaction effect significantly affected dry bean 100-grain weight, dry biomass, and number of leaves per plant at 40 days after emergence. The dry bean/sweet sorghum or cowpea intra-row intercropping and intermediate weeding frequency displayed optimum productivity.

Intercropped maize‐soybean silage: Effects on forage yield, fermentation pattern and nutritional composition

AbstractWe investigated whether the intercropping of maize and soybean could improve the silage nutritional content without reducing the forage yield or worsening silage fermentation process and aerobic stability. Three crop arrangements were studied: maize monoculture, soybean monoculture and maize‐soybean intercropping. The experimental design was completely randomized with 5 replicates per treatment. Maize‐soybean intercropping decreased the dry matter (DM) and grain yield as well as the production of digestible dry matter per hectare. The crude protein content of maize‐soybean intercropped silage was higher compared with maize in monoculture (by 40%), but, on average, both silages presented similar fermentation profile, in vitro digestibility (600 g/kg DM), dry matter loss (37.1 g/kg DM), gas loss (36 g/kg DM) and aerobic stability (60 hr). Soybean‐crop silage presented an elevated content of volatile organic compounds, low lactic acid concentration (2 g/kg DM), high pH (5.26), and greater losses of dry matter (73 g/kg DM) and gas (98.5 g/kg DM) during fermentation. Aerobic stability was higher in soybean‐crop silage (192 hr) due to the high content of volatile fatty acids (butyric acid > 87 g/kg DM) and low contents of residual sugar and lactic acid. In conclusion, maize and soybean intercropping increased crude protein content, but contrary to our hypothesis, the crop association did not result in greater silage digestibility or higher aerobic stability, nonetheless reduced both crop productivity. Additionally, ensiling direct‐cut soybean crop with low DM content is not recommended due to the high risk of undesirable fermentation and nutrient losses.

Lentil yield and crop growth rate are coupled under stress but uncoupled under favourable conditions

Growth and yield can be decoupled in lentil whereby excessive vegetative growth leads to self-shading, reduced pod and seed set, low harvest index and higher risk of disease and lodging. We evaluated the degree of coupling between growth and yield in 20 lentil lines grown in eight environments varying in water and photothermal conditions returning a 10-fold yield range, from 21 to 221 g m−2. Calibration curves between shoot biomass and canopy cover measured with NDVI and green canopy cover measured with Canopeo app were improved with canopy height as a multiplication factor returning a 3-D trait. Calibration curves were used to phenotype shoot biomass and calculate crop growth rate.For the pooled data, yield correlated non-linearly with crop growth rate, with an x-intercept of 0.09 g m−2 [oCd]-1, suggesting a minimum plant size for reproduction, and an inflection point at 0.43 g m−2 [oCd]-1. Yield correlated with biomass and crop growth rate in the more stressful conditions (yield ≤ 107 g m−2) and was decoupled in higher yielding conditions (yield ≥ 170 g m−2). Yield associated with harvest index at all yield levels, but more strongly in high-yielding conditions. Biomass and harvest index correlated in environments with yield ≤ 107 g m−2, and decoupled under more favourable conditions (yield ≥ 170 g m−2). Yield associated with phenology under stress but not in favourable conditions. For the combination of lines and environments in this study, broad sense heritability was 0.96 for flowering time, 0.93 for harvest index, 0.89 for yield, 0.87 for crop growth rate and 0.39 for biomass. Selection for harvest index would improve yield across environments whereas selection for growth rate could further improve yield under stress. Agronomic practices to improve the coupling of yield and growth under favourable conditions need to be explored; for example, using precision seeding to reduce rectangularity of crop arrangement and favour penetration of radiation into the canopy and pod set.

English

Effects of phosphorus rate and crop arrangement on yields and economic benefits in maize-bean cropping systems were investigated for two seasons: Short rains (SR) of 2015 and long rains (LR) of 2016 in Western Kenya. A split plot design with five crop arrangements in the main plots; one row of maize and beans alternating (conventional), maize and beans planted in the same hole (SH), two rows of maize alternating with two of beans (Mbili), sole maize and sole beans, and three P rates; 0, 30, and 60 kg ha-1 in the subplots was used. There were no significant effects of crop arrangement on maize and bean yields in LR but bean yields increased with increasing P rate in both seasons. Within a crop arrangement, maize yields also increased with P rate in the SR. Conventional and Mbili arrangements had similar yields for both beans and maize which were superior to SH at 60 kg P ha-1 in SR. Sole beans significantly out-yielded intercropped ones. Intercropping was only beneficial (LER > 1) with adequate rainfall in SR but financial returns were too low for all the tested practices because of low yields coupled with high production costs and low producer prices. Key words: Crop arrangements, intercropping efficiency, phosphorus.

The Effect of Best Crop Practices in the Pig and Poultry Production on Water Productivity in a Southern Brazilian Watershed

This study analyzes the relation between Brazilian broiler and pig production and water productivity using recently developed reference guidelines on water footprinting for livestock production systems and supply chains. Different rainfed crop arrangements, in different scenarios and producer regions in Brazil, were assessed. Water productivity of broiler feed consumption ranged from 0.63 to 1.38 kg per m3 water input to rainfed summer maize (safra) and from 1.20 to 2.21 kg per m3 water input to winter maize (safrinha) while it ranged from 0.28 to 0.95 kg per m3 water input to rainfed soy. For pig feed consumption, rainfed maize ranged from 0.68 to 1.49 kg per m3 water input (safra) and from 1.30 to 2.38 kg per m3 water input (safrinha) while it ranged from 0.30 to 1.03 kg per m3 water input to rainfed soy. A potential amount of water saving of 0.0336 km3 year−1 and 0.0202 km3 year−1 could be attained for producing broiler and pig feed, respectively, depending on the crop rotation and producer region. The results showed that the evapotranspiration of animal feed production represents more than 99% of the total water consumption for broiler and pig production in the study area. The implementation of best crop practices resulted in higher water productivity values of chicken and pork meat and also improved the rainfall water-saving in comparison to conventional agriculture. Hence, the water productivity of the animal production chain in tropical regions demands a close relation to agriculture in order to attain a better understanding and improvement of rainfall water productivity for animal feed production.