Search

Cover crops can determine positive benefits on soil fertility and rice productivity, although scant attention has been devoted to evaluating the effects of hairy vetch (Vicia villosa Roth) and the incorporation of rice straw with different N fertilization levels on soil N and P availability and crop yields in temperate cropping systems characterized by poorly developed soils. In this study, the effects of cover crops grown before rice in a temperate mono-cropping system (NW Italy) on: (i) crop yields and yield components; (ii) apparent N fertilizer recovery and optimal level of N fertilization with hairy vetch; and (iii) temporal variation of soil available N and P forms during the hairy vetch growth and rice cropping season, have been investigated. The cultivation and incorporation of hairy vetch in the rice cropping system increased grain productivity by 12%, while reducing N mineral fertilization requirements by 33%. Combined with the incorporation of crop residues, hairy vetch provided a N and P input of 178 and 18 kg ha−1, respectively, representing a readily available source for plant uptake over the whole rice cropping season, particularly under anaerobic conditions. This results in a better temporal synchronization of soil N and P availability with crop nutrient demand, leading to a better rice grain productivity and quality performance. [ABSTRACT FROM AUTHOR]

Focuses on the scholarship and teaching about the American South in Italy. Author's research and interest on Southern History; Difficulties in researching Southern History in Italy.

Conventional tillage (i.e. ploughing) that is applied in Italian rice fields ensures high grain yields, but may result in negative effects on physical and chemical fertility of soil. Conservation tillage can be a viable alternative to conventional allowing to reduce the environmental and economic impact of rice cultivation. However, there is limited knowledge on the effects of these alternative tillage systems on rice yield and paddy soil fertility in temperate climates. The aim of this study was to evaluate the effects on yield and soil fertility of conservation tillage in the medium term in temperate rice continuous monoculture system. A six-years monocrop rice experiment (2014–2019) was carried out in North-West Italy, comparing three tillage methods: conventional tillage (ploughing – CT), minimum tillage (MT), and no tillage (NT) combined with three N fertilization rates (N0 , N − 120 kg N ha−1 year−1, and N + − 160 kg N ha−1 year−1). The study evaluated yield, yield components, plant N uptake, apparent N recovery (ANR), soil bulk density, total soil organic carbon (SOC) stock and C and N distribution between different soil organic matter (SOM) fractions. MT showed a similar grain yield to CT , while a 15 % reduction was recorded with NT , which was penalized by low plant density and high soil compaction in the surface layer. Although NT exhibited higher panicle density, spikelets per panicle, and 1000-grain weight than CT and MT , these factors were not sufficient to compensate for the grain yield gap. NT resulted in decreased plant N uptake and ANR, making increasing N fertilization in NT ineffective for recovering the yield gap with CT. After six years, no significant difference was found in SOC stock among the tillage treatments. However, conservation tillage influenced the vertical distribution of SOC, resulting in higher concentration in the superficial soil layer (0–15 cm) compared to CT. MT led to the highest amounts of labile and physically protected SOM in the 0–15 cm layer compared to NT , where lower crop residue input due to lower straw production limited the accumulation of these types of SOM fractions. MT use production resources more efficiently compared to CT and sustains soil fertility by promoting organic matter and nitrogen inputs, facilitating soil aggregation and preventing soil compaction. Yield reductions and excessive soil compaction are the main obstacles to the wide adoption of NT. Minimum tillage is a viable alternative to conventional tillage for improving the environmental and economic sustainability of Italian temperate rice cropping system, while no tillage may only be suitable for marginal and less productive areas. • Minimum tillage is the most suitable conservation tillage system for temperate rice. • No tillage decreases rice yield due to low plant density and high soil compaction. • Conservation tillage does not increase soil C stock in medium term. • Conservation tillage affects the vertical distribution of organic C in paddy soils. [ABSTRACT FROM AUTHOR]

Residue incorporation and organic fertilisation are recommended to increase soil organic matter (SOM) content, thus promoting the provision of multiple ecosystem services. However, the positive effect of crop residue on SOM is often considered rather low, thus requiring a deeper knowledge of their management. In addition, organic fertilisation is thought to be less efficient than mineral. In this context, it is important to understand the response of SOM pools to long-term crop residue incorporation and organic fertilisation and their effect on nutrient cycling and on feed production, in order to judge the sustainability of these practices. We carried out an in-depth multidisciplinary survey to investigate the effect of 28 years of residue incorporation combined with three different nitrogen (N) fertilisation strategies (manure, slurry and mineral) on density fractionated SOM pools differing for their turnover time, and on soil enzymatic activity in a monocropping maize system in NW Italy. Results showed that in the long-term crop production was not altered by organic fertilisation. Organic fertilisation in combination with residue incorporation led to the highest total organic C and total N content down to 90 cm, which was reflected in each SOM pool. In addition, regular applications of crop residue and manures markedly increased C- and N-degrading enzymes, thus enhancing the turnover rates of C and N. We conclude that combining crop residue with organic fertilisation enhanced the provision of regulating services and soil activity, and is a valid approach for maintaining sustainable production in agroecosystems. • Mineral fertiliser N and removal of maize residues deplete SOM and enzyme activities down to 90 cm depth. • Crop residues incorporation and organic fertilisation significantly affect soil TOC and TN contents down to 90 cm depth. • Both practices increase in particular the mineral-associated fraction of TOC and TN. • Organic fertilisation increases stable SOM to a greater depth than crop residues. • Organic fertilisation fosters C- and N- degrading enzyme activities more than crop residues. [ABSTRACT FROM AUTHOR]