Eggplant is a popular vegetable consumed all over the world. Cover cropping is an efficient way of recycling nutrients and reducing inorganic fertilizer requirements to maintain the sustainability of the soil without affecting productivity and profitability. Eggplants (Solanum melongena) (Japanese varieties Hansel and Kamo) were grown in a Piedmont soil with two main treatments, cover crop (CC) and no cover crop (NC), and four sub-fertilizer treatments (T1: 0-0-0, T2: 56-28-112, T3: 84-56-168, and T4: 168-112-224 N-P-K kg/ha), using four replications. The Hansel variety eggplant yield was significantly higher than the Kamo variety. Eggplant yields from CC treatments for both varieties were significantly higher (p < 0.001) than the yields from NC treatments. No significant difference was observed in the yields between T1 and T2 treatments, but the yields from T3 were significantly higher than T1 and T2 and yields from T4 were significantly higher than T3 yields. N released through mineralization of cover crop mixture ranged from 13.33 g/kg at the beginning of the growing season and increased to 18.32 g/kg at the end of the growing season. These results suggest that Japanese eggplants can be successfully grown in the Piedmont area of North Carolina in rotation with cover crops for higher yields. Full article

Adding mulch biomass prior to crop seeding may improve production of tropical soil. We evaluated the response of four bean (Phaseolus vulgaris L.) genotypes to the addition of mulch biomass from Tithonia diversifolia (Hemsl.) Gray and Cajanus cajan L. Millsp. The addition of mulch did not result in significant differences (p < 0.05) in soil characteristics when compared to a control (no mulch addition) except for soil potassium (K), which was significantly greater (p < 0.05) in the T. diversifolia mulch biomass treatment. Bean yield and shoot biomass were significantly greater (p < 0.05) in the mulch biomass treatments compared to the control (no biomass added). In these treatments, Phosphorus (P)-efficient bean genotypes had a significantly greater (p < 0.05) yield and shoot biomass. Bean shoot nutrient concentrations were significantly different (p < 0.05) between mulch biomass treatments and between bean genotypes (P, K and magnesium (Mg) only). Phosphorus utilization and uptake efficiencies were significantly different (p < 0.05) between mulch biomass treatments and between bean genotypes. Bean root biomass was not significantly different (p < 0.05) between mulch biomass treatments, but was significantly different (p < 0.05) between bean genotypes. The number of root nodules was significantly greater (p < 0.05) in the T. diversifolia mulch biomass treatment and was significantly different between bean genotypes. Full article

Cole crops (Brassica vegetables) can pose a significant risk for N losses during the post-harvest period due to substantial amounts of readily mineralizable N in crop residues. Amending the soil with organic C has the potential to immobilize N and thereby reduce the risk for N losses. Four field trials were conducted to determine the effects of organic C amendments (OCA) on N dynamics and spring wheat (Triticum durum L.) harvest parameters proceeding early- and late-broccoli (Brassica olecerea var italica L.) systems in 2009 and 2010. The experimental controls represented the traditional grower practice of incorporated broccoli crop residue (CR-control) and the pre-plant application of N fertilizer (CRN-control) to subsequent spring wheat. Alternative practices were compared to the controls, which included broccoli crop residue removal (CR-removal), an oat (Avena sativa L.) cover crop (CC-oat), and three different OCA of wheat straw (OCA-straw), yard waste (OCA-yard), or used cooking oil (OCA-oil). The treatments, which demonstrated reduced autumn soil mineral N (SMN) concentrations after broccoli harvest, relative to the CR-control, were CR-removal, OCA-straw, and OCA-oil. Although CR-removal and OCA-straw indicated a reduced potential for autumn soil N losses in the early-broccoli system, these practices are not recommended for growers because subsequent spring wheat yield and profit margins were reduced compared to the CR- and CRN-controls. The OCA-oil reduced autumn SMN concentrations by 53 to 112 kg N ha⁻¹ relative to the CR-control after both early- and late-broccoli harvest, suggesting a larger potential for reduced autumn soil N losses, compared to all other treatments. No detrimental effects resulted from the OCA-oil treatment on the subsequent spring yield or grain N. The OCA-oil reduced spring wheat profit margins relative to the CR-control, like the OCA-straw and CR-removal treatments, however profit margins were similar between the OCA-oil and the CRN-control. Therefore, in areas with a high risk of environmental N contamination, growers should consider the OCA-oil practice after cole crop harvest to minimize the risk of N losses. Full article

Appropriate organic amendment management is essential in potato production to increase soil productivity and potato (Solanum tuberosum L.) quality. The objectives of this two-year field study (2004–2005) were to evaluate the effects of organic amendment applications with or without mineral N fertilizer addition on potato yield, N uptake, N use efficiency (NUE), and on disease incidence. The experimental design was a split-plot, which included nine treatments with four different organic amendments applied in fall 2003 or in spring 2004 at a rate of 40 Mg ha⁻¹ (wet basis) and an unamended control in main plots, and N fertilizer rates (0 and 90 kg N ha⁻¹) in sub-plots. Organic amendments consisted of fresh cattle manure (FCM), composted cattle manure (CCM), paper mill sludge with C/N ratio <15 (PMS₁) and paper mill sludge with C/N >15 (PMS₂) applied alone (0 kg N ha⁻¹) or supplemented with mineral fertilizer at a rate 90 kg N ha⁻¹. The N fertilizer rate in the unamended control consisted of 0 and 150 kg N ha⁻¹. No organic amendments were applied in 2005 to evaluate residual effects. Fall and spring applications of FCM, CCM and PMS alone significantly increased N uptake and potato marketable yields by 2.5 to 16.4 Mg ha⁻¹, compared to the unfertilized control. Combining organic amendments with N fertilizer at 90 kg N ha⁻¹ increased potato yields, N uptake, and specific gravity, which were comparable to those obtained in mineral N fertilizer treatments (150 kg N ha⁻¹). Residual effects of organic amendments alone had no significant effects on potato yields or on N uptake compared to the unfertilized control. Potato NUE for FCM, CCM and PMS ranged from 6% to 25% in the first year and from 2% to 8% in the residual year. The NUE values were higher for PMS with lower C/N ratio compared to FCM and CCM. This study did not show any difference between organic amendment applied in spring or fall on potato yield and quality. It was also demonstrated that mineral N fertilizer needed to be combined with organic amendments to sustain potato yield and N nutrition. This study showed that appropriate organic amendment management could increase potato yield and quality and reduce N fertilizer requirement. Full article

High seed cost accompanied by poor germination and seedling performance renders cabbage nursery and field production enterprises unsustainable to many small-scale growers in tropical and sub-tropical countries. In most nurseries, adverse ecological conditions and pest damage are among the major factors responsible for poor seedling performance. The objective of this study was to test the potential use of eco-friendly net (EFN) covers as a low cost technology for sustainable cabbage seedling production. The study was a two-season experiment conducted using a randomized complete block design with five replications and two treatments. Treatments were: the standard open field transplant production (control) and transplant production under 0.4 mm mesh polyethylene net covering. EFN covering increased both temperature and relative humidity, enhanced seedling growth and reduced insect pest damage. Seed germination and seedling emergence were under the net covering earlier. Higher seed germination and seedling survival were recorded under the EFN treatment, indicating a potential for reducing the seed requirement per unit area of cabbage production. Seedlings grown under the nets had higher stomatal conductance and leaf chlorophyll content; furthermore, they grew taller, with more leaves within a shorter period of time compared to the control seedlings. The use of EFN in cabbage nurseries offers a sustainable technology for enhancing seedling performance by reducing pest infestation, thereby lowering production cost and improving the grower’s income. Full article

Establishing bare-root transplants in Florida, United States, is an inefficient water-consuming activity. Between 3500 and 5500 m³/ha are applied with sprinkler irrigation to lower temperatures around the transplant crown and aid early root development, but more than 97% of the water volume runs off the polyethylene-covered beds. Research has been conducted to evaluate the feasibility of producing containerized (plug) short-day cultivar transplants under Florida conditions, the effect of continuous and intermittent low-volume sprinklers on transplant establishment and the use of kaolin clay to reduce stress on young transplants. Research results demonstrated that growers may have alternatives to reduce water use and pumping costs during strawberry transplant establishment by the following: (a) plug transplants can be produced from mother plants from Florida’s subtropical weather without chilling conditioning and still be competitive in the winter market; (b) using continuous and intermittent low-volume sprinkler irrigation saves between 16% and 33% of the water volumes for strawberry establishment; and (c) using kaolin clay showed to be a low-cost (US$63/ha plus application costs) investment to reduce irrigation volumes by at least 30%. Full article

Common bean (Phaseolus vulgaris L.) is an important legume crop worldwide. However, abiotic and biotic stress limits bean yields to <600 kg ha⁻¹ in low-income countries. Current low yields result in food insecurity, while demands for increased yields to match the rate of population growth combined with the threat of climate change are significant. Novel and significant advances in genetic improvement using untapped genetic diversity available in crop wild relatives and closely related species must be further explored. A meeting was organized by the Global Crop Diversity Trust to consider strategies for common bean improvement. This review resulted from that meeting and considers our current understanding of the genetic resources available for common bean improvement and the progress that has been achieved thus far through introgression of genetic diversity from wild relatives of common bean, and from closely related species, including: P. acutifolius, P. coccineus, P. costaricensis and P. dumosus. Newly developed genomic tools and their potential applications are presented. A broad outline of research for use of these genetic resources for common bean improvement in a ten-year multi-disciplinary effort is presented. Full article

The options for increasing food production by at least 70% over the next four decades so as to keep pace with a rapidly increasing human population are bedeviled by erratic climatic conditions, depleted arable lands, dwindling water resources and by the significant environmental and health costs for increasing the use of agrochemicals. Enhanced productivities through “smart” crop varieties that yield more with fewer inputs is a viable option. However, the genetic similarities amongst crop varieties—which render entire cropping systems vulnerable to the same stresses—coupled with unvarying parental materials limit the possibilities for uncovering novel alleles of genes and, hence, assembling new gene combinations to break yield plateaux and enhance resilience. Induced mutation unmasks novel alleles that are harnessed to breed superior crop varieties. The historical antecedents, theoretical and practical considerations, and the successes of induced mutations in crop improvement are reviewed along with how induced mutagenesis underpins plant functional genomics. The roles of cell and molecular biology techniques in enhancing the efficiencies for the induction, detection and deployment of mutation events are also reviewed. Also, the integration of phenomics into induced mutagenesis and the use of pre-breeding for facilitating the incorporation of mutants into crop improvement are advocated. Full article

In light of the environmental challenges ahead, resilience of the most abundant field crop production systems must be improved to guarantee yield stability with more efficient use of nitrogen inputs, soil and water resources. Along with genetic and agronomic innovations, diversification of northern agro-ecosystems using inter-seeded legumes provides further opportunities to improve land management practices that sustain crop yields and their resilience to biotic and abiotic stresses. Benefits of legume cover crops have been known for decades and red clover (Trifolium pratense) is one of the most common and beneficial when frost-seeded under winter wheat in advance of maize in a rotation. However, its use has been declining mostly due to the use of synthetic fertilizers and herbicides, concerns over competition with the main crop and the inability to fully capture red clover benefits due to difficulties in the persistence of uniform stands. In this manuscript, we first review the environmental, agronomic, rotational and economical benefits associated with inter-seeded red clover. Red clover adaptation to a wide array of common wheat-based rotations, its potential to mitigate the effects of land degradation in a changing climate and its integration into sustainable food production systems are discussed. We then identify areas of research with significant potential to impact cropping system profitability and sustainability. Full article

Through the development of superior plant varieties that benefit from high agrochemical inputs and irrigation, the agricultural Green Revolution has doubled crop yields, yet introduced unintended impacts on environment. An expected 50% growth in world population during the 21st century demands novel integration of advanced technologies and low-input production systems based on soil and plant biology, targeting precision delivery of inputs synchronized with growth stages of crop plants. Further, successful systems will integrate subsurface water, air and nutrient delivery, real-time soil parameter data and computer-based decision-making to mitigate plant stress and actively manipulate microbial rhizosphere communities that stimulate productivity. Such an approach will ensure food security and mitigate impacts of climate change. Full article

The Green Revolution has enabled Asian countries to boost their crop production enormously. However, Africa has not benefitted from this agricultural revolution since it did not consider local, but important crops grown in the continent. In addition to their versatile adaptation to extreme environmental conditions, African indigenous crops provide income for subsistence farmers and serve as staple food for the vast majority of low-income consumers. These crops, which are composed of cereals, legumes, vegetables and root crops, are commonly known as underutilized or orphan crops. Recently, some of these under-researched crops have received the attention of the national and international research community, and modern improvement techniques including diverse genetic and genomic tools have been applied in order to boost their productivity. The major bottlenecks affecting the productivity of these crops are unimproved genetic traits such as low yield and poor nutritional status and environmental factors such as drought, weeds and pests. Hence, an agricultural revolution is needed to increase food production of these under-researched crops in order to feed the ever-increasing population in Africa. Here, we present both the benefits and drawbacks of major African crops, the efforts being made to improve them, and suggestions for some future directions. Full article