Transparent mulch

The European Union (EU) countries use 160,000 tons in transparent crop covering, 148,000 tons in black silage film, 60,000 in transparent mulch films, and around 33,000 in stretch films [44]. 

Figure 11.4 Total yield and ripe fruit yield. Ethephon = E ( /ha) (a) not mulched (b) smoke-coloured mulch (c) transparent mulch (d) not mulched + E (1.5 + 1.5) (e) smoke-coloured mulch + E (0.5) (f) transparent mulched + E (0 5) (g) not mulched + E (3), (h) smoke-coloured mulch + E (1), (i) transparent mulch + E (1) (I) not mulched + E (1.5) (m) smoke coloured mulch + E (1 5). (n) transparent mulch + E(1.5).

The benefits of opaque or transparent mulching films allow the following observations. 

Figure 5, Performance of Envirocare systems in long term heat ageing. 25 im LLDPE transparent mulch film oven exposed at 50 C.

Figure 5. Embrittlement times for 25 nm LLDPE transparent mulch film with six different Envirocare additives exposed outdoors in soil contact in Pontecchio Marconi, Italy (110 kLy yr ). Data are times (dark bars) and absorbed energy (light bars) for embrittlement.

Chellemi DO, Rhoads FM, Olson SM, Rich JR, Murray D, Murray G, Sylvia DM (1999) An alternative, low-input production system for fresh market tomatoes. Am J Altem Agric 14 59-68 Chen Y, Katan J (1980) Effect of solar heating of soils by transparent poliethilene mulching on their chemical properties. Soil Sci 130 271-277... 

Mahrer Y (1979) Prediction of soil temperature of a soil mulched with transparent polyethylene. J Appl Meterol 18 1263-1267... 

Mahrer YA (1980) A numerical model for calculating the soil temperature regime under transparent polyethylene mulches. Agric Meteorol 22 227-234 Mahrer Y, Katan J (1981) Spatial soil temperatures regime under transparent polyethilene mulch. 

Numerical and experimental studies. Soil Sci 131 82-87 Mahrer Y, Naot O, Rawaitz E, Katan J (1984) Temperature and moisture regimes in soils mulched with transparent polethylene. Soil Sci Soc Am J 48 362-367 Malathrakis NE, Loulakis MD (1989) Effectiveness of the type of polyethylene sheet on soil solarization. Acta Hort (ISHS) 255 235-242... 

Stapleton JJ, Ferguson L (1996) Solarization to disinfest soil for containerized plants in the inland valleys of California. In Proceedings of the annual international research conference on methyl bromide alternatives and emissions reduction. Orlando, FL, 4-6 November 1996, p 6 Stapleton JJ, Garza-Lopez JG (1988) Mulching of soils with transparent (solarization) and black polyethylene films to increase growth of annual and perennial crops in southwestern Mexico. Trop Agric 65 29-33... 

Mulching transparent or black LDPE, double-layered white and black LDPE for reflective purposes, photodegradable LDPE. 

Some applications are the same t)rpical for LDPE transparent blown films, mulch films for agriculture, films for package and bags, and also blown bottles, filaments, injection moulded and thermoformed products [69]. 

As far as the cultivation is concerned, mulching plays a decisive role. This technique consists of covering the soil with a very thin transparent or opaque plastic film, at the time of sowing or transplanting. The conditions which are controlled by this technique are the soil and weather characteristics and the plant environment. These relate to factors such as thermal imbalance, prevention of evaporation and particularly the elimination of negative effects of cold wind and excessive heat. These will manifest themselves in an increase in the quantity and the quality of the yield, in water saving and in earlier maturity. 

It is well known that crops mulched with transparent film produce more than unmulched crops or crops mulched with opaque film. The lower concentration of nitrogen found in plot F is due to the higher output of vegetables and roots which means higher nitrogen uptaking from the soil by the crop. The lower... 

Mulched cultivation with two types of photodegradable film, natural transparent and opaque, both of a thickness of 12 pm. 

Figure 3 shows failure data for samples of a transparent LLDPE mulch film formulated with Envirocare additives and exposed in a circulating air oven at 50°C. Failure was taken as the point of embrittlement of the film it can be varied by choosing the appropriate amount of additive and can be accelerated significantly and controllably. 

Figure 4 shows data for samples of PE mulch film exposed to artificial UV ageing in a Xenon weatherometer. The lifetime to embrittlement of transparent films can be reduced significantly by using the appropriate additive. Addition of carbon black to unmodified film produces a major stabilizing effect, which can easily be overcome by the additive. 

Figure 6. Embrittlement and disappearance times for 25 pm transparent LLDPE mulch films with four Envirocare additives exposed in soil contact in Bologna, Italy (110 kLy yf ).

By removing weeds and eliminating soil compaction, mulch eliminates the need for cultivation. By this we further avoid damage to roots and stunting or killing of plants. Not only this, fertilizer and water requirements of the field get controlled. To trap heat, transparent polyethylene is more effective compared to black or smoke-grey films. Due to clear films, soil temperature may rise to 5.58°C, but under black Alms, it is 1.7-2.78°C. The temperature of the atmosphere will be maintained by the polymer bags. 

Another application, under development, is the low tunnel technique. These low tunnels, the diameter of which is about Im, are set over mulch in order to increase the mulch effect by a greenhouse effect. They are made of transparent plastic and fixed on the soil using small iron arches. The function of these low tunnels is similar to a greenhouse. Typically, melons are cultivated under these structures. In 2003 (Jouet, 2003), the above applications accounted for 12,860,000 ha (670,0001 of plastic) for mulching and 900,000 ha (170,0001 of plastic) respectively for low tunnels in the world. 

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