Organic matter water extract, or so-called ‘tea’, may be used to correct nutrient deficiencies in crops or enhance their defense systems. Such tea mixtures are prepared locally by Mediterranean farmers to offset a multitude of constraints, particularly a scarcity of organic manure or high synthetic input costs. However, the diverse range of tea production and usage practices and farmers' underlying rationales have yet to be thoroughly studied. Yet locally they constitute real alternatives that allow farmers to maintain their income levels while reducing reliance on chemical inputs. The main objective of this study was to gain insight into farmers' rationale and practices regarding the production of homemade dry manure tea (HMT) in North Africa, while also highlighting the benefits perceived by farmers. Nearly 50 interviews with farmers were thus conducted in three irrigated cropping areas in Morocco, Algeria and Tunisia. Our results showed that HMT is widely used in intensified family horticultural cropping systems that usually rely on drip irrigation and chemical fertilization. The analysis of farmers' practices revealed that HMT was generally made from aged manure that was pure or consisted of a mixture of sheep, cow or poultry dung. The production protocol varied in terms of drenching techniques, maceration time, container volume and type, and filtration techniques. Farmers applied the derived tea via the drip irrigation system, regularly or with a limited number of applications. The analysis of farmers' rationales and perceptions regarding HMT clearly highlighted that they felt that these practices played a positive role. HMT was considered to improve vegetative growth, yield and, to a lesser extent, soil properties. These benefits could in turn lead to decreased use of synthetic fertilizers by farmers, while boosting their income. The increased understanding of HMT and the underlying rationales showcased in this study could help scientists better analyze and assess these practices in the future. The findings could also facilitate improvement and wider dissemination of these practices to achieve more sustainable irrigation systems in the intensified irrigated cropping areas that abound in North Africa.

A field experiment was conducted near Davis, CA, during the 2003 and 2004 summer growing seasons to compare weed control, yield, and fruit quality in different irrigation and tillage systems in processing tomato. Trial design was a subplots with the main plots as subsurface drip irrigation or furrow irrigation, subplots were standard tillage or conservation tillage, and sub-subplots were herbicide or no herbicide. The hypothesis was that subsurface drip irrigation could limit surface soil wetting and thus inhibit germination and growth of weeds equal to or better than standard tillage and/or herbicides. In both 2003 and 2004, weed densities in the subsurface drip irrigation treatments were over 98% lower than the levels in furrow irrigation treatments. In addition, weed densities were lower in the subsurface drip–conservation till–no herbicide treatment than in any of the furrow irrigation treatments, including the furrow irrigation–standard tillage–herbicide treatments. The time required for a hand-hoeing crew to remove weeds was 5 to 13 times greater in furrow irrigation treatments compared to subsurface drip irrigation treatments. Weed biomass on beds at tomato harvest was 10 to 14 times greater in the furrow systems as compared to the subsurface drip irrigation systems. These results demonstrate the effectiveness of subsurface drip irrigation in controlling weed germination and growth, compared to tillage or herbicide applications. Tomato yield was higher in the subsurface drip irrigation treatment compared to furrow irrigation in 2004. Herbicide treatment increased yield in 2004, but only in the furrow irrigation treatment in 2003. Fruit brix level was not related to treatment in 2003, but was lower in the subsurface drip irrigation plots in 2004. These results indicate that subsurface drip irrigation can reduce weed competition in conservation tillage systems, without requiring herbicide applications.

Introduction. Their physical and chemical properties make sandy tin tailings unsuitable for agricultural purposes without proper fertilizer and crop management practices. An attempt was made to use these tailings for sustainable production of pineapple using fertilization and irrigation techniques. Therefore, the objective of the study was to determine the effect of ground sucker size and levels of fertilizer used on yield and nutrient accumulation in plant components of pineapple cv. Josapine grown on sandy tin tailings. Materials and methods. Three fertilizer levels (plot 1, plot 2 and plot 3) containing N, P, K, Ca, Mg and Cu in solution and three classes of ground suckers (> 70 cm, 70–40 cm and < 70 cm) were used. They were arranged in a randomized complete block design with three replicates. There were 32 plants in each experimental plot. Each plot received a similar quantity of Fe, B, Mn, Zn and Mo. At harvest, each plant’s parts were divided into fruit, leaves, stem and roots. The dry matter yield and nutrient contents of each pineapple part were analyzed and recorded. Results and discussion. The highest and the lowest amounts of dry matter were 397 g·plant–1 (size > 70 cm) and 96 g·plant–1 (size < 70 cm), respectively. Total dry matter accumulation was greater (26%) for plot 1 than for plots 2 and 3. Substantial amounts of the dry matter accumulation occurred in leaves (45.0%) and fruit (34.0%) and less in stems (16.0%) and roots (5%). A similar pattern was also observed for the total (major and micro-) nutrient accumulation in the plant components. Besides the fruit parameters, the length of the pineapple stem is an important factor affecting the yield of pineapple, either expressed on a fresh (R2 = 0.904***) or dry (R2 = 0.855***) weight basis. Conclusion. Ground sucker size is a very important factor for successful production of a high fruit yield and quality of pineapple planted on sandy tin tailings.