Control of Apple Replant Disease Using Mixed Cropping with Brassica juncea or Allium fistulosum

Evidence indicates that Allium and Brassica species which release bioactive compounds are widely used in bio-fumigation to suppress soil-borne diseases. However, the active molecules of such plant residues are easily volatilized. In this study, we conducted mixed cropping of the apple tree with Allium fistulosum or Brassica juncea; the results demonstrated that such mixed cropping significantly improved the growth of the grafted apple seedlings and alleviated apple replant disease (ARD) for two years. The terminal-restriction fragment length polymorphism profile results showed that the soil fungal community demonstrated distinct variation and diversity in terms of composition. A. fistulosum and B. juncea significantly improved the Margalef, Pielou, and Shannon indices. In addition, the analyses of clone libraries showed that A. fistulosum and B. juncea promoted the proliferation of antagonistic fungi such as Mortierella, Trichoderma, and Penicillium, and inhibited the proliferation of pathogens such as Fusarium. Fusarium. Proliferatum (F. proliferatum) was abundant in replanted soil and proved to be an aggressive pathogen of apple seedlings. Our findings thus indicate that apple tree mixed cropping with A. fistulosum and B. juncea was an effective long-term method for modifying the resident fungal community and alleviating ARD.

Mixed Cropping of Dwarf Napiergrass (Pennisetum purpureum cv. Mott) with Indigofera (Indigofera zollingeriana) using an Alley Cropping System

Background: Mixed cropping of forage grasses and legumes can potentially improve the performance of herbivores. However, the feasibility of grasses mixed-cropped with legumes should be examined at different plant densities. Aim: This study aimed to evaluate the growth characters and forage chemical composition in dwarf napiergrass (Pennisetum purpureum cv. Mott) with Indigofera (Indigofera zollingeriana) grown using alley cropping. Methods: Three densities of dwarf napiergrass with Indigofera, i.e., high density (2 and 1 plants m-2, respectively); medium density (1.33 and 1 plants m-2, respectively); and low density (1 and 1 plants m-2, respectively) were applied under rainfed conditions in Makassar. Results: Plant density significantly affected growth characteristics, such as plant height and tiller density in dwarf napiergrass (p<0.05), and non-significantly affected plant height and branch density (p>0.05) in Indigofera. Plant density did not affect the yielding ability at the first defoliation and annual total of yields (p>0.05), except at the second defoliation when the dry matter production of dwarf napiergrass peaked in the low plant density treatment (p<0.05). In terms of chemical composition, plant density significantly affected fiber concentrations of acid detergent fiber and neutral detergent fiber, which were lowest at low plant densities (p<0.05). The acid detergent lignin and cellulose concentrations tended to be lower at low plant densities, but the differences were not significant (p>0.05). Conclusion: We consider that alley cropping systems for dwarf napiergrass and Indigofera are suitable if low plant densities are employed in the region.

Profitability of various cropping patterns among arable crop farmers in Niger State, Nigeria

Descriptive Statistics and Net Farm Income model was used to analyze data collected from 120 Arable Farmers who adopted various cropping patterns in Niger State, Nigeria. The study specifically examined the socio-economic characteristics of arable farmers, profile the cropping patterns adopted, examined the profitability and highlighted the constraints to crop production among arable farmers in the study area. Results obtained from the study show that crop farming in the area is a male dominated. The mean age of farmers was 33years, 98.3% were married, 80.8% had one form of education or the other and 68.4% adopted a three-crop mix pattern in their crop production. Two and three crop mixes enterprise were profitable than sole cropping when gross income per ha was used as an index of profitability. Profitability was higher in single crop enterprise when returns/man day was used as an index but was higher in a two and three crop mix enterprise when net returns per ha was used as a measure of profitability. Bad roads, drought, theft of farm produce, poor extension per farm advisory services and lack of credit facilities respectively were the constraint to crop production. The study concludes that mixed cropping enterprises was more profitable than sole cropping. We recommend the promotion of mixed cropping among arable farmers for increased profitability and income to farm households, that the constraints identified be addressed by all concerned authorities so as to sustain crop production, reduce food insecurity and eradicate hunger and poverty among arable farmers in the area and Nigeria as a whole.

Does the inverse farm size productivity hypothesis hold for perennial monocrop systems in developing countries? Evidence from Kenya

The inverse farm size and productivity relationship (IR) is a recurring theme in the literature. However, most previous studies were undertaken within a setting of mixed cropping systems. In this article, we investigate the effect of farm size on productivity within the context of a perennial monocropping system, acute competition for farmland, frequent subdivision of farms and declining yields. We apply household survey data of smallholder tea farms in western Kenya and consider both technical efficiency (TE) and the yield per hectare as indicators of productivity. The findings show that the effect of farm size on productivity is nonlinear, with TE initially declining and then rising with farm size. The findings also demonstrate that the farm size and productivity relationship is important for perennial monocrops and that the use of robust measures of productivity is important for the IR. The findings have important implications for agricultural policy in developing countries.

Performance de l’association mixte sorgho-niébé sur les productivités du sorgho et des sols en zone Soudano-Sahélienne du Burkina Faso

Dans la zone soudano-sahélienne du Burkina Faso, la performance des associations mixtes sorgho-niébé reste faible bien que les nombreux services écosystémiques rendus par les associations céréales-légumineuses soient connus. L’objectif de la présente étude a été de comprendre la performance des associations mixtes sorgho-niébé sur la productivité du sorgho et du sol. L’étude a consisté à conduire des tests multi-locaux avec de petits agriculteurs familiaux de la région Nord du Burkina Faso. Des traitements à base de zaï simple (ZS), zaï + 9 t ha-1 de substrats organiques (ZF) et zaï + 9 t ha-1 de substrats organiques + 50 kg ha-1 d’urée (ZFN) ont été testés en 2013, chaque traitement étant répété 9 fois. En 2014, le traitement ZFN a été remplacé par le traitement zaï + 9 t ha-1 de substrat organique + 600 kg ha-1 de Burkina Phosphate (ZFP). Chaque parcelle élémentaire a abrité l’association mixte sorgho-niébé et la monoculture du sorgho. Les résultats ont montré que l’association mixte sorgho-niébé a généralement entrainé une dépréciation des rendements du sorgho par rapport à la monoculture du sorgho. Par contre, une performance significative de +58% en 2014 et un accroissement de +10% en 2013 des rendements totaux grains de sorgho et de niébé ont été enregistrés par rapport à la monoculture du sorgho. Une grande efficacité d’acquisition des nutriments par le sorgho associé au niébé a été enregistrée en comparaison à la monoculture du sorgho. Pour une meilleure performance des cultures mixtes sorgho-niébé, les traitements ZS et ZF sont à recommander pour augmenter les rendements totaux grains de niébé et de sorgho ainsi que l’acquisition de N dans les grains du sorgho ; les traitements ZFN et ZFP sont, quant à eux, sont à recommander pour améliorer la fertilité résiduelle en N et P des sols dans la région Nord du Burkina Faso. English title: Performance of sorghum-cowpea mixed cropping system on sorghum and soils productivities in the Sudano-Sahelian zone of Burkina Faso In Sudano-Sahelian zone of Burkina Faso, the performance of sorghum and cowpea mixed cropping system remains low although the many ecosystems provided associated by cereal and legume mixed or intercropping system are known. The objective of this study was to understand the performance of these sorghum and cowpea mixed cropping system on the productivities of sorghum and soils. The study consisted to multi-local tests with small family farmers in the northern region of Burkina Faso. Treatments based on simple zaï (ZS), zaï + 9 t ha-1 of organic substrates (ZF) and zaï + 9 t ha-1 of organic substrates + 50 kg ha-1 of urea (ZFN) were tested in 2013, each treatment being replicated at 9 times. In 2014, the ZFN treatment was replaced by the zaï + 9 t ha-1 of organic substrate + 600 kg ha-1 of Burkina Phosphate (ZFP). Each elementary plot was occupied by sorghum and cowpea mixed cropping system and monocropping sorghum. The results showed that the yields of sorghum mixed by cowpea generally lowered than the yields of monocropping sorghum. In contrast, a significant performance of +58% in 2014 and an increase of +10% in 2013 on total sorghum and cowpea grains yields were recorded compared to monocropping sorghum. The high efficiency of nutrient acquisition by sorghum in mixed cropping system with cowpea was recorded compared to monocropping sorghum. For better performance of sorghum and cowpea mixed cropping system, ZS and ZF treatments are recommended to increase total sorghum and cowpea grains yields, the N acquisition in sorghum grains, and ZFN and ZFP treatments were suggested to improve residual N and P fertility of soils in the northern region Burkina Faso.

Mapping Crop Types and Cropping Systems in Nigeria with Sentinel-2 Imagery

Reliable crop type maps from satellite data are an essential prerequisite for quantifying crop growth, health, and yields. However, such maps do not exist for most parts of Africa, where smallholder farming is the dominant system. Prevalent cloud cover, small farm sizes, and mixed cropping systems pose substantial challenges when creating crop type maps for sub-Saharan Africa. In this study, we provide a mapping scheme based on freely available Sentinel-2A/B (S2) time series and very high-resolution SkySat data to map the main crops—maize and potato—and intercropping systems including these two crops on the Jos Plateau, Nigeria. We analyzed the spectral-temporal behavior of mixed crop classes to improve our understanding of inter-class spectral mixing. Building on the Framework for Operational Radiometric Correction for Environmental monitoring (FORCE), we preprocessed S2 time series and derived spectral-temporal metrics from S2 spectral bands for the main temporal cropping windows. These STMs were used as input features in a hierarchical random forest classification. Our results provide the first wall-to-wall crop type map for this key agricultural region of Nigeria. Our cropland identification had an overall accuracy of 84%, while the crop type map achieved an average accuracy of 72% for the five relevant crop classes. Our crop type map shows distinctive regional variations in the distribution of crop types. Maize is the dominant crop, followed by mixed cropping systems, including maize–cereals and potato–maize cropping; potato was found to be the least prevalent class. Plot analyses based on a sample of 1166 fields revealed largely homogeneous mapping patterns, demonstrating the effectiveness of our classification system also for intercropped classes, which are temporally and spatially highly heterogeneous. Moreover, we found that small field sizes were dominant in all crop types, regardless of whether or not intercropping was used. Maize–legume and maize exhibited the largest plots, with an area of up to 3 ha and slightly more than 10 ha, respectively; potato was mainly cultivated on fields smaller than 0.5 ha and only a few plots were larger than 1 ha. Besides providing the first spatially explicit map of cropping practices in the core production area of the Jos Plateau, Nigeria, the study also offers guidance for the creation of crop type maps for smallholder-dominated systems with intercropping. Critical temporal windows for crop type differentiation will enable the creation of mapping approaches in support of future smart agricultural practices for aspects such as food security, early warning systems, policies, and extension services.

Evaluation of Microbial Diversity, Community Composition and Function in Mixed Cropping Systems Using Three Legume Species Under the Application of Biochar or Chemical Fertiliser

Mixed cropping systems involve utilising multiple crop species on the field and diversifying aboveground plants. However, several contradicting results have been reported regarding their effects on soil microbial diversity. Therefore, to evaluate the effects of different leguminous species used in mixed cropping systems and the types of fertiliser on the diversity of soil microbes, a pot study was performed under maize/legume mixed cropping systems with one of three legumes, including cowpea [Vigna unguiculata (L.) Walp.], velvet bean [Mucuna pruriens (L.) DC.] and common bean (Phaseolus vulgaris L.) , and one of three types of fertiliser treatments, namely chemical fertiliser (CF), carbonised chicken manure (CM) or the lack of fertiliser (Ctr). 16S rRNA analyses were conducted using the soils sampled from each pot for soil bacterial diversity assessment, and Tax4Fun2 was used for bacterial functional prediction analysis. A decrease in microbial diversity after CM application was observed in the soil with velvet bean + maize (MM) compared to the Ctr treatment, whereas an increase in microbial diversity was observed in the soil with common bean + maize (PM) in the same condition. With CM application, the abundance of treatment-unique bacteria increased with PM treatment, whereas their decrease was observed with MM treatment. In contrast, the abundance of dominant microbes, including Thaumarchaeota, Chloroflexi, Planctomycetes and Verrucomicrobia, was significantly lower in PM but higher in MM after CM application. Functional prediction analysis indicated that the dominant bacteria were involved in CM decomposition processes and nitrification in MM treatment. Legume species-dependent factors, including nutrient absorption and root exudate composition, might be important concerning soil bacterial diversities.