Apparent N Balance in Organic and Conventional Low Input Cropping Systems

The determination of nutrient surplus is one of the indicators of potential N losses from the agricultural system to the environment. An experiment was started in 1998 in Central Italy to evaluate the soil surface N balance of an organic and a conventional low input cropping system over a long term crop rotation. Results at the end of a 6-year crop rotation showed an estimated N surplus in organic system 1.3-2 times higher than in conventional system while N content in the top soil was not different in the two systems, so that organic system should have involved a higher N loss from that soil layer

Early interspecific interference in the wheat/faba bean (Triticum aestivum/ Vicia faba ssp. minor) and rapeseed/squarrosum clover (Brassica napus var. oleifera/Trifolium squarrosum) intercrops

Most of research on intercrops evaluate performances and interference between species on the basis of final yield, while little knowledge is available on the interference in early stages and at the root level, at least for cultivated intercrops. In fact, in the few studies on this subject species are often combined minding at experimental needs ( e.g. common substrate, temperature and water requirements, easy root separation) more than at their actual use in the farm. The present work evaluates interspecific interference during early developmental stages for two intercrops of agricultural interest: soft wheat-faba bean and rapeseed-squarrosum clover. Improving this knowledge would help intercrop growth modelling and rational cultivation. The experiments were carried out on soft wheat ( Triticum aestivum ), faba bean ( Vicia faba var. minor ), rapeseed ( Brassica napus var. oleifera ) and squarrosum clover ( Trifolium squarrosum ), germinated and grown until 32 days after sowing (DAS) as one-species stands or as wheat/faba bean and rapeseed/squarrosum clover intercrops, with different densities and proportions for the two species in each couple. Germination was studied in controlled-temperature chamber, plantlet growth was studied on pots in the greenhouse. During germination no interspecific interference was observed for both wheat/faba bean and rapeseed/squarrosum clover intercrops. During plantlet growth, interspecific interference occurred in both intercrops causing variations in whole plant and root dry matter accumulation. In the wheat/faba bean intercrop each species suffered from the competitive effect of the companion species and faba bean was the dominant species when present in lower proportion than wheat. The unexpectedly high aggressivity of faba bean may be explained either with the greater seed size that could have represented an initial advantage within the short duration of the experiment or with the competition towards wheat for substrate N which is not usual in the open field for a N fixing species. In the rapeseed/squarrosum clover intercrop, rapeseed was facilitated by squarrosum clover, while squarrosum clover suffered from the competitive effect of rapeseed, which was the dominant species. The resource use efficiency of intercrops as compared to that of one-species crops was lower in the wheat/faba bean couple, not much different in the rapeseed/squarrosum clover one. In both couples, the best performance was observed when the ratio of the dominant species was lower than that of the companion species (number of plants in the ratio 1:3)

Nine-year results on maize and processing tomato cultivation in an organic and in a conventional low input cropping system

Nine-year results on yields and apparent balances of organic matter and nitrogen (N) are reported for maize and processing tomato cultivated in a long term comparison trial between an organic and a conventional low-input system in Central Italy. In every year, above ground biomass and N accumulation of each cash crop and green manure, including weeds, and the partitioning between marketable yield and crop residues were determined. Apparent dry matter and nitrogen balances were calculated at the end of each crop cycle by taking into account the amounts of dry matter and ex-novo N supplied to the system as green manure legume Ndfa ( i.e. an estimate of N derived from the atmosphere via symbiotic fixation) and fertilizers, and those removed with marketable yield. Processing tomato complied with organic cultivation better than maize. As compared to the conventional crop cultivation, organic tomato provided similar yields, used supplied N more efficiently and left lower residual N after harvest, with lower related risks of pollution. Organic maize yielded less than conventional one. The main limitation for organic maize was the low N availability during initial growth phases, due to either low N supply or low rate of N release from incorporated green manure biomass. In both organic and conventional cultivation the system sustainability could be improved by an appropriate crop rotation: wheat in fall winter likely prevented leaching loss of mineral N in both systems; green manure crops in the organic system allowed to either trap and recycle soil mineral N or supply ex novo legume Ndfa to the soil, with benefits in mitigation of N pollution and improvement in self-sufficiency of the system

Yield and apparent dry matter and nitrogen balances for muskmelon in a long-term comparison between an organic and a conventional low input cropping system

Nine-year yields and apparent balances of dry matter and nitrogen (N) are reported for muskmelon cultivated in a long-term comparison trial between an organic and a conventional low input system in Central Italy. In every year, yield, above ground biomass and N accumulation of each cash crop, green manure and weeds, and the partitioning between marketable yield and crop residues were determined. Apparent dry matter and nitrogen balances were calculated at the end of each crop cycle by taking into account the amounts of dry matter and ex novo N supplied to the system as green manure legume Ndfa (i.e., an estimate of N derived from the atmosphere via symbiotic fixation) and fertilisers, and those removed with marketable yield. Differences between systems varied across years. On average, organic muskmelon yielded 16% less than the conventional one, while the fruit quality was similar in the two cropping systems. Fruit ripening began one week later and it was more scaled than in the crop grown conventionally. This was the consequence of a slow initial growth of the organic crop, due to inadequate green manure N total supply or timing of N release. Moreover such a wide spaced crop (0.5 plants m–2, in rows 2 m apart) was not efficient in intercepting N released from green manure biomass incorporated broadcast. Compared to the conventional crop management, the organic crop management resulted in much higher organic matter supply to the soil and in higher residual N after harvest. Thus, the choice of cultivating wheat just after melon to prevent postharvest residual N loss appears a key strategy especially in organic systems. Fall-winter green manure crops contributed to the self-sufficiency of the organic system by supplying muskmelon with either N absorbed from the soil or ex novo legume Ndfa

Eleven-year results on soft and durum wheat crops grown in an organic and in a conventional low input cropping system

Eleven-year results on yields and apparent balances of organic matter and nitrogen (N) are reported for soft and durum wheat crops grown in the BIOSYST long-term experiment for the comparison between an organic and a conventional low-input system in Central Italy. The N supply to organic wheat consisted of 40 kg N ha–1 as poultry manure plus the supposed residual N left by green manures carried out before the preceding summer vegetable, while the N supply to conventional wheat consisted of 80 kg N ha–1 as mineral fertilisers, split in two applications of 40 kg ha–1 each, at tillering and pre-shooting. In every year, above ground biomass and N accumulation of each wheat species, including weeds, and the partitioning between grain yield and crop residues were determined. Apparent dry matter and N balances were calculated at the end of each crop cycle by taking into account the amounts of dry matter and N supplied to the system as fertilisers, and those removed with grain yield. Soft wheat yielded more than durum wheat. For both species, grain yield and protein content were more variable across years and generally lower in the organic than in the conventional system. In both systems, grain yield of both species resulted negatively correlated with fall-winter rainfall, likely for its effect on soil N availability. Both species caused a lower return of biomass and a higher soil N depletion in the organic than in the conventional system. Our experiment confirmed that winter wheat can help exploit the soil N availability and reduce N leaching in fall winter, especially after summer vegetables, but in stockless or stock-limited organic systems it needs to be included in rotations where soil fertility is restored by fall winter green manures to be carried out before summer crops

Phenolic content and antioxidant activity of einkorn and emmer sprouts and wheatgrass obtained under different radiation wavelengths

Abstract Sprouted seeds represent intriguing ready-to-eat micro-scale vegetables for the healthy food market, since they are tasty and rich in bioactive compounds. However, sprouts have been recently proposed as a source for the extraction and purification of several phytochemicals to be used in food supplementation or pharmaceutics. Recently, there has been an industrialization of sprout production, carried out indoor, often with use of artificial light, which have implications on biomass yield and composition, and on energetic and economic costs. This work investigates the effects of different radiation wavelengths from light emitting diodes (LED) on free and bound phenolics and antioxidant activity of sprouts and wheatgrass of einkorn (Triticum monococcum L. ssp. monococcum) and emmer ([(Triticum turgidum L. spp. dicoccum, (Schrank ex Schubler) Thell.)]). After 3 days of grain incubation in the dark, three light treatments were applied, labelled as BLUE (447 and 470 nm), RED (627 and 655 nm), and SUN (447, 470, 505, 530, 590, 627, 655 nm), for a same total photon flux density (PFD) of 200 μmol m−2 s−1. Sprouts were harvested at 5 days after sowing (DAS) and wheatgrass at 9 DAS. The effect of light was generally not significant for sprouts, much greater and species-specific for wheatgrass: BLUE in einkorn and RED in emmer generally increased free and total content of polyphenol (PC), tannins (TC), flavonoid (FC) and phenolic acids (PAs). The antioxidant activity was increased by BLUE in einkorn and decreased by RED in both species. BLUE and RED resulted energy saving compared to SUN

Techniques and machines for conservation and organic agriculture: the S.M.O.C.A. project.

The combination of low environmental impact farming techniques and conservation agriculture techniques is considered not feasible due to some limitations, mainly including is the strong dependence of conservation cropping systems by chemical control of weeds and the use of mineral fertilizers, which are considered essential for supporting to acceptable levels of crop productions. In order to apply the techniques of reduced tillage also in organic and integrated agriculture, is therefore indispensable, on one hand, the availability of specific versatile and efficient machines for non-chemical cover-crop management, weed control and sod-seeding/planting, on the other hand, the optimization of cropping systems in function of improved nutrient cycling and preventive weed control. The SMOCA project (Smart Management Conservation of Organic Agriculture) aims to integrate organic cropping systems and conservation agriculture techniques in three different scenarios (arable open field, open field vegetables and orchards) thanks to development of machines and technical itineraries that allow to apply the reduced tillage techniques even in the absence of pesticides. Within this project, prototypes of machines were realized in order to implement conservation cropping systems with high energy efficiency. For each scenario, three technical itineraries were compared: - control (INT): based on integrated agriculture without use of conservation agriculture techniques. The use of agrochemicals is allowed in accordance with the disciplinary for integrated production; - organic system (ORG): based on the organic agriculture, involves the use of cover crops (managed as green manure) and soil tillage. The non chemical management of weed flora is achieved with preventive methods and direct methods (mechanical and thermal weed control); - organic and conservation system (ORG +): based on the deep integration between the principles of conservation agriculture and organic farming. The system aims to achieve an almost continuous coverage of the soil through the use of no-tillage techniques and cover crops managed as living or dead mulches. The study of the overall sustainability of the different systems in comparison is conducted by means of a detailed analysis of the following aspects: - agronomic; - energy and environmental; - economic. The environmental effect of the compared systems will be mainly assessed through the study of the following aspects: greenhouse gas emissions, nutrient balance, preservation of soil quality, biological nitrogen fixation, conservation of water resources in the soil and the life cycle assessment (LCA). The efficiency and the impact of different management techniques are also continuously monitored on the orchard and vegetable crops through the study of the fruits of growth dynamics, thanks to an innovative methodology that uses a network of growth sensors spatially distributed in the field. The final product quality is also evaluated through the analysis of their levels of nutraceutical compounds. The research project is still ongoing and the prototypes of machines realized are presented in this paper

Integrazione di tecniche di agricoltura biologica e conservativa in sistemi colturali con crescente intensità ecologica: il progetto F.I.R.B. SMOCA

Il progetto SMOCA (Smart Management of Organic Conservative Agriculture) (2014- 2017) mira ad incrementare la sostenibilità dei sistemi colturali integrati/biologici mediante l’introduzione di tecniche di agricoltura conservativa, finalizzate alla riduzione dei consumi energetici e al miglioramento della fertilità del terreno. In SMOCA saranno sviluppate macchine e strategie agronomiche innovative che permettano di applicare le tecniche di lavorazione ridotta anche in assenza di mezzi chimici di sintesi