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-A two-year experiment was carried out to study the effects of applying untreated Olive Wastewater (OWW), treated OWW and olive pomace compost as soil amendments on both rye-grass growth and soil characteristics. We analysed growth parameters (Leaf Area Index, and fresh and dry weight), leaf green colour (SPAD readings), N uptake of the rye-grass and chemical soil characteristics. The results indicate that the highest untreated OWW application increased growth parameters by 18.2% in 2001 and by 41.1% in 2002, indicating the possible use of OWW as an amendment to rye-grass. We observed a significant increase in total, extracted and humified organic carbon, and humification parameters. No accumulations of heavy metals in the soil were observed. Furthermore, the N content in OWW was used by the rye-grass for plant growth that increases N uptake, and consequently, dry matter accumulation.olive wastewater / olive pomace compost / perennial rye-grass / controlled environment lysimeter / trace metals / organic carbon

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-The application of conventional agricultural practices, e.g. deep soil tillage and repeated, plentiful mineral fertilisation, can lead to a progressive deterioration of soil fertility, especially in Mediterranean environments characterised by scanty rains and high summer temperatures. As a consequence, to maintain high levels of both crop productivity and soil organic matter and to improve some soil properties, a reduction of agricultural inputs and a greater supply of organic material are needed. In the light of these considerations, we carried out a two-year field experiment in Southern Italy to determine the effects of reduced soil tillage and municipal solid waste compost application on growth parameters, production and quality of sugar beet crops, and on both soil chemical characteristics and mineral nitrogen deficit. Two soil tillage depths were compared: conventional tillage, till 40-45 cm and shallow tillage, at 15-20 cm. Within each soil tillage, the following N-fertilising strategies were tested: (1) mineral fertilisation, with 100 kg N ha −1 ; (2) organic fertilisation with municipal solid waste compost at 100 kg N ha −1 ; (3) mixed fertilisation, with 50% of organic N as municipal solid waste compost, and 50% of mineral N; and (4) slow-release organic-mineral N fertiliser, at 100 kg N ha −1 . All these treatments were compared with a lower level of mineral fertiliser at 50 kg N ha −1 , and with an unfertilised control. Our findings show first the absence of a significant difference in root and sucrose yields between reduced tillage and deep tillage; as shown by roots (36.02 t ha −1 ) and sucrose (3.41 t ha −1 ) yields for reduced tillage and 35.76 and 3.51 t ha −1 , respectively, for the deepest tillage. Secondly, among the N treatments, the mixed organic-mineral N fertilisation gave productions statistically not different from mineral N fertilisation; as shown by root yields (36.38 versus 36.40 t ha −1 ) and sucrose yields (3.56 versus 3.65 t ha −1 ). Third, the mixed organic-mineral N induced a reduction of 13.2% in α-amino N content by comparison with the mineral treatment of 100 kg N ha −1 . Fourth, our results showed that the applications of the municipal solid waste compost increased the extracted and the humified organic carbon by +27.7 and +25.4%, compared with the mineral fertiliser, and did not raise the content of heavy metals. These findings highlighted that in Southern Italy it is sustainable to adopt alternative sugar beet production, safeguarding crops' quantitative and qualitative performance, decreasing the production costs and using the natural resources better.sugar beet / soil tillage depths / municipal solid waste / yield / quality / soil characteristics / mineral N deficit

Nitrogen (N) is one of the most growth restricting nutrients in cereal grain and represents one of the highest input costs in agricultural systems; therefore, environmental and economic considerations require the effective use of N fertilizer in plant production. This study was conducted for three years to better understand wheat plant response to optimize N fertilizer and how to reduce the risk of ground water pollution.Two of the most important durum wheat cultivars in Southern Italy and four N fertilization levels (0, 60, 120, and 180 kg N ha −1 , indicated as N0, N60, N120, and N180, respectively) were compared in this experiment. During plant growth, fresh and dry matter, plant nutritional state (SPAD readings and stem nitrate content), and N uptake were determined. At harvest, plant N content, N uptake, grain yield, yield components and quality were determined, allowing the calculation of the pre-and postanthesis N uptake and the N utilization efficiency indices. Furthermore, at the beginning and at the end of each year, soil mineral N was measured to calculate mineral N deficit in the soil.The results indicated that the treatment with 120 kg N ha −1 of fertilizer ensures a good balance between yield and N utilization. In fact, N180 and N120 showed similar yield (3.01 and 3.07 t ha −1 , respectively) and protein content (13.7 and 13.5 %). Meanwhile, throughout the three-year experiment, N180 presented the highest final mineral N content in the soil at the end of the cropping cycles, increasing the amount of N available for leaching. The N120 treatment showed the same values of N utilization indices as compared to N180, indicating that further doses of N fertilizer did not increase wheat N utilization. Plant N status shows that it is possible to modify the N fertilization to reach its optimum level during plant growth, in accordance with variable weather conditions, F. Montemurro et al.and consequently the plants requirements. The mean treatments of the preanthesis N uptake were about 67.5% of the total N uptake, and it was significantly and positively correlated with wheat yield. On the contrary, the postanthesis N uptake showed positive correlation with grain protein content, confirming the importance of late N supply in grains quality. The variation of weather conditions affected winter wheat yield, quality, N utilization and plant N status, but any difference throughout years was found between N180 and N120, confirming that higher N rate did not influence wheat growth, yield, and N uptake.

-We studied the effects of municipal solid waste compost applied to soil on sunflower nitrogen (N) uptake, N utilisation, yield, soil mineral N deficit and soil characteristics. One unfertilised control was compared with the optimal N dose for the sunflower crops in the test area (100 kg N ha -1 ) supplied as: organic fertilisation, with municipal solid waste compost; mineral fertilisation, with ammonium nitrate; and mixed fertilisation, with 50 kg N ha -1 from compost and 50 kg N ha -1 from mineral nitrogen. The results obtained showed that the compost, at the end of the experiment, modified the soil chemical properties. In particular, it significantly improved available phosphorus (111.3% increase for compost treatment in respect to 57.6% for the control), maintained almost the same level of exchangeable potassium (6.0% reduction for compost treatment in respect to 9.8% for the control), and significantly enhanced total soil organic matter (50.0% vs. 32.1%) and extracted organic carbon (16.6% vs. 11.8%). In addition, the application of this material did not increase the total content of heavy metals. The results showed that the municipal waste compost did not modify N uptake, utilisation, or efficiency of sunflower plants. The mean value of N uptake during the vegetative stage was 60.9%, while postanthesis N uptake reached only 39.1% and was positively and significantly correlated with yields and total N uptake, showing that the late N absorption could influence yield performance of sunflower cropped in Mediterranean conditions. Furthermore, the compost, alone or in association with mineral fertiliser, allowed similar yield performance as mineral fertilisation in oil yield (1.51, 1.48 and 1.58 t ha -1 , for the three treatments, respectively) and protein yield (0.66, 0.64 and 0.65 t ha -1 , respectively).sunflower / municipal solid waste / soil properties / nitrogen uptake and utilisation / mineral N deficit / yield

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