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Yield response of crisphead lettuce and kohlrabi to mineral and organic fertilization in different soils
No full textThe paper deals with the yield response of crisphead lettuce and kohlrabi cultivated in different soils (sandy, loamy and peat-clay) and fertilized with different rates and types of fertilizers (mineral and organic
Controlled drainage and crop production in a long-term experiment in North-Eastern Italy
No full textCrop productivity under controlled drainage was studied in long-term field experiment with shallow fluctuating water table in North-Eastern Italy. Fourteen years of hydrological and yield data, including winter wheat, su- garbeet, soybean and maize, were collected over two monitoring periods (1995–2002 and 2006–2013). Controlled drainage (CD) and free drainage (FD) were tested in combination with open ditches (O) and sub- surface pipes (P) systems. CD reduced outflow waters by 69%, respect to FD. Wheat produced on average 4.9 t ha−1. P system was more productive (up to 14.2%) in drier years characterized by sparse and more intense spring rainfalls, due to reduced runoff and increased infiltration. O system was more productive (up to 27.9%) in wet years with frequent rainfalls after sowing, as water was removed faster from soil surface avoiding water- logging. Soybean produced on average 3.2 t ha−1, with higher yield (5.7% more) in P, probably due to better and more uniform topsoil moisture conditions. Sugarbeet sucrose production showed no univocal response to CD, as a great variety of factors were involved in determining root growth and sucrose concentration. Maize yield had great variability among the years, depending on weather. However, the best results were always obtained with CD (up to 14.5 t ha−1 of grain), showing a definite increase in productivity (on average, with CD grain maize produced 27.3% more, and silage maize 4.0% more). The benefits of CD on maize yield were more pronounced in years with wet springs followed by summer droughts. Subirrigation in CD helped to achieve higher yields when soil moisture content was declining due to prolonged dry periods.
In our environment, CD proved to be extremely helpful in reducing water outflows and increasing maize yield, mitigating drought stress
Ornamental plants for floating treatment wetlands: Preliminary results
Full text linkFloating treatment wetlands (FTWs) represent a novel ecotechnology for the treatment of different types of wastewaters in natural or artificial water bodies, through the use of traditional rooted emergent macrophyte species supported by floating rafts. Although many studies have reported the treatment performances of FTWs, showing an excellent aptitude for removing nutrients, heavy metals as well as suspended solids, the investigation of vegetation has not received much attention up to now, especially for herbaceous ornamental plant species that could form an interesting opportunity to improve water quality and the esthetic-ornamental value of urban water bodies. For this reason, a pilot scale FTW was installed in Northern Italy to assess the growth performances of eleven wetland species having ornamental features: Canna indica L., Pontederia cordata L., Thalia dealbata Fraser ex Roscoe, Acorus calamus L., Juncus effusus L., Iris laevigata L., Mentha aquatica L., Oenanthe javanica (Blume) DC., Caltha palustris L., Sparganium erectum L. and Zantedeschia aetiopica (L.) Srengel. For these species, a suitability index was elaborated that considers plant survivability, above-mat biomass production, nitrogen uptake, root length and root-shoot ratio. On this basis, the results obtained clearly indicated that C. indica, P. cordata and T. dealbata were the most suitable species for FTW due to their high vigor and colonization of the floating mats (1638.9 g m(-2), 483.4 g m-2, 566.1 g m(-2) of above-mat dry biomass, respectively; 38.8 cm, 62.0 cm, 43.8 cm root length, respectively; 0.8, 0.9, 1.2 root-shoot ratio, respectively), survival (100%), nitrogen uptake (15.1 g m(-2), 15.0 g m(-2), 15.7 g m(-2) respectively). On the contrary, A. calamus, S. erectum and Z. aetiopica did not present adequate features for use in FTWs
Quality response of crisphead lettuce and kohlrabi to mineral and organic fertilization in different soils
No full textTwo levels of fertilization (medium and high), using mineral fertilizer (MF) alone, farmyard manure (FyM) alone, or a combination of MF and FyM, together with non-fertilized controls, were tested in northeastern Italy in three different soils (clay, peaty-clay and sandy). The clay and peaty-clay soils demonstrated to be the most suitable for the quality of both lettuce and kohlrabi, showing high incidence of heavier heads and larger-sized stems, respectively, for the two crops, low dry matter and high raw protein content. In lettuce, a higher nitrate content was observed when plants were grown in peaty-clay soil (spring- and autumn-grown lettuce) and in clay soil (autumn-grown lettuce). Fertilization showed different effectiveness on crop quality in relation to soil type. For spring-grown lettuce in sandy soil, the distribution of 200,100 and 280 kg ha-1 of N, P2 O5 and K2O as mixed fertilization gave qualitative performance (head weight, uniformity, shape, dry matter and raw protein content) similar to those of more fertile soils. Fertilization also improved quality in clay and peatyclay soils, but the effects were less evident than in sandy soil. Autumn-grown lettuce benefited by the residual effect of fertilization. Kohlrabi gave the best stem size and homogeneity in peaty-clay soil, with 100, 50 and 140 kg ha-1 of N, P2O5 and K2O, as mineral fertilizer. Clay soil also proved to be suitable for this crop, especially when mixed fertilization was used. In sandy soil, the quality of the product was lower even when large amounts of nutrients were applied. In both lettuce and kohlrabi, the nitrate content of the edible product was only slightly influenced by fertilization
Treatment performances of floating wetlands: A decade of studies in North Italy
No full textFloating treatment wetlands (FTWs) are one of the most recent eco-technologies to treat low-quality polluted wastewaters in already existing retention ponds, without subtracting other soil surface for the treatment of wastewaters. This study assessed the depuration performances of eight different FTWs (1 pilot-scale and 7 full-scale plants) treating municipal wastewaters, agricultural runoff and digestate liquid fraction, in North Italy. The concentration of different pollutants was monitored before and after the FTWs barriers: total nitrogen (TN), nitrate nitrogen (NO3-N), ammonia nitrogen (NH4-N), total phosphorus (TP), orthophosphate (PO4-P), chemical oxygen demand (COD) and turbidity. Considering all the case studies, pollutants inflowing concentrations were highly variable, due to the different composition of wastewaters used in the trials (TN: 0.3–520.0 mg L−1, median value 19.1 mg L−1; NO3-N: <0.001–61.5 mg L−1, median value 2.6 mg L−1; NH4-N: <0.001–310.0 mg L−1, median value 3.6 mg L−1; TP: 0.02–44.9 mg L−1, median value 5.7 mg L−1; PO4-P: <0.001–32.9 mg L−1, median value 4.1 mg L−1; COD: 2.1–6152.0 mg L−1, median value 67.5 mg L−1). Wastewater nitrogen forms and COD concentrations were reduced after passing the FTW with median abatements of 44.1% for TN, 34.6% for NO3-N, 16.7% for NH4-N, and 25.2% for COD. Only Phosphorus concentrations were not affected by the FTWs. Wastewater turbidity ranged from 3.4 to 3075.0 NTU and the median value of 77.7 NTU was significantly reduced by 22.1% after the FTWs, thus suggesting that plant root systems were active in physical wastewater filtration. In three case studies E. coli was also monitored and abatements ranged from 19.5 and 95.1%. The results obtained after ten years of study indicated that FTWs represented an efficient and economic wastewater management system, which provided a positive ecosystem service and therefore reduced the human footprint on the environment
Maize yield and N dynamics after cover crops introduction
Full text linkThe use of cover crops (CCs) is widely suggested as a sustainable agricultural practice. Nevertheless, conflicting results have been reported about the short-term effect of CCs on cash crop yields and the soil nitrogen (N) dynamics. Within this framework, the present study aims to examine the short-term impact of CC introduction into a conventional agricultural system on silage maize yield and the N dynamics (maize N uptake, N use efficiency (NUE), soil nitrate content (Nmin), and apparent soil N mineralization and immobilization processes) in northern Italy. The CC systems (∼5.5 ha) included a fixed treatment (FI) with a gramineous species (triticale), a 2-year gramineous-legume species succession (SU) (rye, clover), and a weed-covered control treatment (NoCC). In the first year, triticale and rye had the same total (aboveground + root) final biomass (2.5 Mg ha−1 on average), C:N ratio (29), and N uptake (36.4 kg ha−1). However, triticale developed faster in the first winter months. Both grass species equally reduced the soil Nmin content over the winter season (as valid catch crops), but they caused apparent N immobilization during the following maize growing season. In the second year, clover produced the same total biomass as triticale did (1.8 Mg ha−1), but with a higher total N content (72.5 kg ha−1) and lower C:N ratio (27) which determined a lower apparent N immobilization. The introduction of CCs did not affect the yield of maize. During the maize growing season, lower N uptake and NUE were recorded after CCs grasses species cultivation compared to clover and NoCC. These observations suggest that a key aspect to be considered when dealing with CCs is understanding the N mineralization-immobilization processes related to CC residue decomposition, which might determine N availability for the subsequent crop and in turn its production quality (N uptake), even when the yield is not affected
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