Perforated mulch film and crop cultivation system comprising perforated mulch film

Abstract

A crop cultivation system and mulch (1) itself, the crop cultivation system comprising at least one plant bed (8), a polyethylene mulch (1) having a specific pattern of perforations (2) per plant bed (8), and a drip irrigation system comprising a drip irrigation line (6) per plant bed (8).

Description

Technical Field

[0001] The invention relates to a mulch film with a specific perforation pattern and a crop cultivation system, which comprises at least one plant bed, a mulch film for each plant bed and a drip irrigation system comprising a drip irrigation line for each plant bed. Background Art

[0002] Rice is one of the most basic staples in the diets of billions of people around the world. In the 2020 / 2021 crop year, more than 500 million metric tons of rice were consumed worldwide. However, rice cultivation is notoriously intensive, and successfully growing rice using conventional methods requires large amounts of water and is physically and financially demanding on rice farmers.

[0003] Like all agriculture, rice farming is affected by weather conditions, which are becoming increasingly unreliable due to ongoing climate change, with an increasing incidence of both periods of water shortage (i.e. drought) and periods of water surplus (e.g. heavy rains).

[0004] Even without the challenges described above, maximizing productivity is always preferred regardless of the crop being grown. While significant developments have been made in this area, including improvements in crop rotation and other such farming techniques, further improvements through the application of specific irrigation technologies are very welcome, especially if they can increase yields at lower costs and with reduced labor requirements. Summary of the invention

[0005] The present invention is based on the discovery that a new type of mulch film (or covering film), preferably in combination with a specific drip irrigation system, can be used to improve crop yields and farming results, especially when growing rice.

[0006] In a first aspect, the present invention relates to a crop cultivation system comprising:

[0007] i) at least one plant bed;

[0008] ii) one rectangular polyethylene mulch according to the first aspect per plant bed, the one rectangular polyethylene mulch according to the first aspect per plant bed covering said plant bed; and

[0009] iii) a drip irrigation system comprising one drip line per plant bed and a series of regularly spaced drip outlets along said drip line,

[0010] wherein each rectangular polyethylene mulch film, being a monolayer or a multilayer film, has a regular array of perforations, the perforations being symmetrically spaced along two lines on either side of a first axis, the first axis being parallel to the length of the mulch film and being located equidistant from the long side of the mulch film, wherein each line of perforations is parallel to the first axis, the shortest distance between the center of each perforation and the first axis being defined as A, wherein the perforations are regularly spaced along a line parallel to the first axis, the centers of adjacent perforations along either of the two lines having a spacing defined as B between them, wherein B / A is in the range of 1.5 to 2.0,

[0011] wherein each drip irrigation line is positioned along a first axis of each mulch film, and

[0012] The spacing between individual drip outlets along the drip irrigation line is defined as E, and E / B is in the range of 1.5 to 2.0.

[0013] In another aspect, the present invention relates to a rectangular polyethylene mulch film as a single layer film or a multilayer film, the rectangular polyethylene mulch film having a regular array of perforations, wherein the perforations are symmetrically spaced along two lines on both sides of a first axis, the first axis being parallel to the length of the mulch film and being located equidistant from the long side of the mulch film, wherein each line of perforations is parallel to the first axis, the shortest distance between the center of each perforation and the first axis being defined as A, wherein the perforations are regularly spaced along lines parallel to the first axis, and the centers of adjacent perforations along either of the two lines have a spacing defined as B, wherein B / A is in the range of 1.5 to 2.0.

[0014] definition

[0015] When the term "comprising" is used in the present description and claims, other non-specified elements of major or minor functional importance are not excluded. For the purposes of the present invention, the term "consisting of" is considered to be a preferred embodiment of the term "comprising". If a group is defined hereinafter as including at least a certain number of elements, this should also be understood to disclose a group that is preferably composed of only these elements.

[0016] When an indefinite or definite article is used, for example "a", "an" or "the" when referring to a singular noun, this includes a plural of that noun unless otherwise specified. DETAILED DESCRIPTION

[0017] Mulch

[0018] In one aspect, the invention is directed to a mulch film.

[0019] An exemplary ground membrane 1 is depicted in FIG. 1 .

[0020] The ground film is a rectangular polyethylene ground film 1.

[0021] This means that the mulch film 1 must be rectangular in shape. The term "oblong" means that the mulch film has two straight parallel long sides 5, and the exact nature of the shorter end of the mulch film is not limited. For example, a rectangle is an example of a rectangle in which the ends are parallel, straight and perpendicular to the long sides. For example, the ends may also be curved or straight with curved corners. The exact form of the ends of the film is not critical to the present invention. Although the mulch film 1 in Figure 1 is shown as a rectangle with curved corners, this shape is only one of the many possible rectangular shapes that the film can adopt and is not intended to limit this shape. It is preferred that the mulch film 1 is rectangular in shape.

[0022] Furthermore, the ground film must be made of polyethylene, i.e., made of an ethylene-based polymer containing at least 50 wt% of ethylene monomer. Preferably, the ethylene content of the ethylene-based polymer is at least 60 wt%, more preferably at least 70 wt%, still more preferably at least 80 wt%, most preferably at least 90 wt%. If comonomers are present in the polyethylene, it is preferred that any comonomer is selected from C3 to C 12 The alpha olefin is more preferably selected from C4 to C8 alpha olefins.

[0023] It is preferred that the ground film 1 comprises polyethylene in an amount in the range of 85 to 100 wt%, more preferably in the range of 90 to 100 wt%, most preferably in the range of 95 to 100 wt%.

[0024] In addition to the polyethylene as described above, the ground film 1 may also contain additives (Ad). The additives (Ad) are selected from additives known in the art, preferably selected from the group consisting of antioxidants, stabilizers, fillers, colorants, nucleating agents, antistatic agents and mixtures thereof.

[0025] These additives are generally commercially available and are described, for example, in “Plastic Additives Handbook” by Hans Zweifel, 5th edition, 2001, pages 871 to 873.

[0026] As illustrated in Figure 1, a rectangular polyethylene ground membrane 1 is primarily defined by its shape, particularly the perforations in the membrane.

[0027] The rectangular polyethylene mulch has a regular array of perforations 2 that are spaced symmetrically along two lines 3 on either side of a first axis 4. The first axis is parallel to the length of the mulch 1 (i.e., parallel to the two parallel long sides 5). The first axis 4 is located equidistant from the long sides 5 of the mulch 1. Each line 3 of perforations is parallel to the first axis 4. The perforations are regularly spaced along the lines 3 that are parallel to the first axis 4.

[0028] The shortest distance between the center of each perforation 2 and the first axis 4 is defined as A. In other words, the distance between the line 3 and the first axis 4 is A (where the first line passes through the center of each perforation).

[0029] The distance (ie, the pitch) between the centers of adjacent perforations 2 that are regularly spaced along any of the two lines 3 is defined as B.

[0030] The ratio B / A must be in the range of 1.5 to 2.0, more preferably in the range of 1.6 to 1.9, most preferably in the range of 1.6 to 1.8.

[0031] It is preferred that the perforations are all of the same shape and size.

[0032] It is particularly preferred that each perforation is substantially circular. As will be appreciated by those skilled in the art, films have a tendency to stretch and / or deform, which means that any perforation that has been cut in a circular shape may no longer be a perfect circle in nature. The term substantially circular encompasses perforations that are no longer a perfect circle due to stretching / deformation. The diameter of the substantially circular perforation is defined as C.

[0033] The ratio C / A is preferably in the range of 0.20 to 0.75, more preferably in the range of 0.25 to 0.70, most preferably in the range of 0.30 to 0.67.

[0034] The ratio C / B is preferably in the range of 0.10 to 0.45, more preferably in the range of 0.15 to 0.42, most preferably in the range of 0.18 to 0.40.

[0035] In addition, the distance between the two long sides of the rectangular polyethylene mulch (ie, the width of the rectangular polyethylene mulch) is defined as D.

[0036] It is preferred that the ratio D / A is in the range of 4-14, more preferably in the range of 5-12, most preferably in the range of 6-10.

[0037] Although the mulch film according to the first aspect can be used for various types of crops, it is preferred that it is suitable for growing rice.

[0038] The ratios B / A, C / A, C / B and D / A provided above are applicable to each crop; however, if the crop is rice, the absolute value of the distance A to D can be defined more precisely.

[0039] In absolute terms, it is preferred that the distance A is in the range of 10 to 20 cm, more preferably in the range of 12 to 18 cm, most preferably in the range of 13 to 17 cm.

[0040] It is preferred that the distance B is in the range of 17 to 33 cm, more preferably in the range of 20 to 30 cm, most preferably in the range of 23 to 27 cm.

[0041] It is preferred that the distance C is in the range of 3 to 12 cm, more preferably in the range of 4 to 11 cm, most preferably in the range of 4 to 10 cm.

[0042] It is preferred that the distance D is in the range of 60 to 210 cm, more preferably in the range of 75 to 180 cm, most preferably in the range of 90 to 150 cm.

[0043] In a particular embodiment, distance A is in the range of 10 to 20 cm, distance B is in the range of 17 to 33 cm, distance C is preferably in the range of 3 to 12 cm and distance D is in the range of 60 to 210 cm.

[0044] More preferably, distance A is in the range of 12 to 18 cm, distance B is in the range of 20 to 30 cm, distance C is preferably in the range of 4 to 11 cm and distance D is in the range of 75 to 180 cm.

[0045] Most preferably, distance A is in the range of 13 to 17 cm, distance B is in the range of 23 to 27 cm, distance C is preferably in the range of 4 to 10 cm and distance D is in the range of 90 to 150 cm.

[0046] The rectangular polyethylene ground film 1 can be a single-layer film or a multi-layer film. If the film is a multi-layer film, each layer is a polyethylene layer. Preferably, the rectangular polyethylene ground film 1 is a multi-layer film, more preferably a 3-layer film.

[0047] If the rectangular polyethylene ground film 1 is a 3-layer film, the layers of the film are referred to as an outer layer (OL) facing away from the ground, a core layer (CL) located between the other two layers, and an inner layer (facing the ground).

[0048] The outer layer of the ground film preferably comprises a polyethylene component AOL. Preferably, the component AOL is a linear low density ethylene polymer (LLDPE).

[0049] Component AOL

[0050] Preferably, component AOL is a multimodal linear low density ethylene polymer, more preferably a multimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, such as a bimodal linear low density ethylene copolymer. More preferably, component AOL is a copolymer of ethylene and 1-butene or 1-hexene, most preferably a copolymer of ethylene and 1-butene.

[0051] Preferably, the component AOL has a mass of 915 to 925 kg / m 3 and an MFR2 measured according to ISO 1133 of 0.1 to 0.4 g / 10 min.

[0052] Such multimodal LLDPE and its production are described, for example, in WO 2004 / 000933 A1, pages 9 to 12.

[0053] The component AOL preferably has a value of 918 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a density of 0.1 to 0.4 g / 10min, more preferably 0.15 to 0.30 g / 10min.

[0054] Preferably, the total amount of comonomers present in component AOL is from 2.0 to 7.0 mol%, more preferably from 2.5 to 6.5 mol%, most preferably from 3.0 to 6.0 mol%.

[0055] In a particularly preferred embodiment, component AOL is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, most preferably 1-butene, and component AOL has an MFR2 of 0.15 to 0.30 g / 10min, and / or an MFR5 of 0.50 to 1.00 g / 10min, and / or an MFR of 12 to 24 g / 10min. 21 , and / or 920 to 925 kg / m 3 density, and / or a molecular weight distribution (MWD) of 10 to 25, and / or an M of 10 to 18 kg / mol n , and / or 150 to 300 kg / mol of M w , and / or MFR from 60 to 150 21 / MFR2 ratio (FRR 21 / 2 ) and / or MFR from 16 to 30 21 / MFR5 ratio (FRR 21 / 5 ).

[0056] As component AOL, the resin Borstar FB1200 produced by Borouge can be used.

[0057] The core layer (CL) of the turf film is made of a core layer composition that includes components that contribute specifically to the mechanical properties of the turf film and maintain the optical properties of the turf film, such as light transmittance.

[0058] Component ACL

[0059] The core layer composition may comprise component ACL. Preferably, component ACL is a linear low density ethylene polymer (LLDPE).

[0060] Preferably, component ACL is a multimodal linear low density ethylene polymer, more preferably a multimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, such as a bimodal linear low density ethylene copolymer. More preferably, component ACL is a copolymer of ethylene and 1-butene or 1-hexene, most preferably a copolymer of ethylene and 1-butene.

[0061] Preferably, the component ACL has a mass of 915 to 925 kg / m 3 and an MFR2 measured according to ISO 1133 of 0.1 to 0.4 g / 10 min.

[0062] Such multimodal LLDPE and its production are described, for example, in WO 2004 / 000933 A1, pages 9 to 12.

[0063] Component ACL has 918 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a density of 0.1 to 0.4 g / 10min, more preferably 0.15 to 0.30 g / 10min.

[0064] Preferably, the total amount of comonomers present in component ACL is from 2.0 to 7.0 mol%, more preferably from 2.5 to 6.5 mol%, most preferably from 3.0 to 6.0 mol%.

[0065] In a particularly preferred embodiment, component ACL is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, most preferably 1-butene, and component ACL has an MFR2 of 0.15 to 0.30 g / 10min, and / or an MFR5 of 0.50 to 1.00 g / 10min and / or an MFR of 12 to 24 g / 10min. 21 , and / or 920 to 925 kg / m 3density, and / or a molecular weight distribution (MWD) of 10 to 25, and / or an M of 10 to 18 kg / mol n , and / or 150 to 300 kg / mol of M w , and / or MFR from 60 to 150 21 / MFR2 ratio (FRR 21 / 2 ) and / or MFR from 16 to 30 21 / MFR5 ratio (FRR 21 / 5 ).

[0066] As component ACL, the resin Borstar FB1200 produced by Borouge can be used.

[0067] Preferably, component ACL is present in the core layer composition in an amount of 50 to 80 wt%, more preferably 55 to 75 wt%, based on the total weight of the core layer composition of the turf film.

[0068] Component BCL

[0069] The core layer composition of the core layer CL of the three-layer ground film preferably further comprises component BCL, which component BCL has a molecular weight of 915 to 925 kg / m 3 Linear low density ethylene polymer (LLDPE) having a density of 2 and an MFR2 measured according to ISO 1133 of 0.5 to 3.0 g / 10 min.

[0070] LLDPE is well known in the art and is produced in a polymerization process using a catalyst.

[0071] Preferably, component BCL is a multimodal linear low density ethylene polymer, preferably a multimodal ethylene copolymer of ethylene and one or more comonomers selected from α-olefins having 4 to 10 carbon atoms, more preferably a bimodal ethylene copolymer of ethylene and one or more comonomers selected from α-olefins having 4 to 10 carbon atoms.

[0072] In a particular embodiment, component BCL is a multimodal copolymer, preferably a bimodal copolymer, of ethylene with two comonomers selected from α-olefins having 4 to 10 carbon atoms, preferably a multimodal copolymer of ethylene with two comonomers selected from 1-butene and 1-hexene, i.e. a multimodal terpolymer.

[0073] Preferably, the ethylene copolymer has an MFR of 13 to 30. 21 / MFR2 ratio and / or MWD of 6 or less.

[0074] Preferably, the ethylene copolymer comprises or consists of a multimodal polymer of ethylene and one or more comonomers selected from α-olefins having 4 to 10 carbon atoms, the ethylene copolymer having an MFR of 13 to 30. 21 / MFR2 ratio and MWD of 6 or less.

[0075] Such multimodal ethylene copolymers are disclosed in e.g. WO 2016 / 083208.

[0076] The multimodal ethylene copolymer preferably has an MFR2 of 0.6 to 2.0 g / 10 min and particularly preferably 1.0 to 1.8 g / 10 min.

[0077] Preferably, the multimodal ethylene copolymer has a molecular weight of 915 to 925 kg / m 3 , more preferably 916 to 920 kg / m 3 density.

[0078] The multimodal ethylene copolymer preferably has an MFR of 13 to 30, more preferably 15 to 25. 21 / MFR2 ratio.

[0079] The multimodal ethylene copolymer preferably has a MWD of 6 or less and typically greater than 1, more preferably 3-5.

[0080] The α-olefin comonomer having 4 to 10 carbon atoms of the multimodal ethylene copolymer is preferably 1-butene and / or 1-hexene.

[0081] Preferably the total amount of comonomers present in the multimodal ethylene copolymer is from 0.5 to 10 mol%, preferably from 1 to 8 mol%, more preferably from 1 to 5 mol%, still more preferably from 1.5 to 5 mol% and most preferably from 2.5 to 4 mol%.

[0082] In a preferred embodiment, the multimodal ethylene copolymer is a bimodal copolymer, i.e. it comprises a low molecular weight component and a high molecular weight component, and the multimodal ethylene copolymer has an MFR2 of 1.0 to 1.8 g / 10min, and / or an MFR5 of 3.0 to 5.0 g / 10min, and / or an MFR of 20 to 40 g / 10min. 21 , and / or 916 to 920 kg / m 3 density, and / or a molecular weight distribution (MWD) of 3 to 5, and / or an M of 15 to 25 kg / mol. n , and / or 80 to 140 kg / mol of M w , and / or MFR of 15 to 25 21 / MFR2 ratio (FRR 21 / 2), and / or MFR of 6 to 9 21 / MFR5 ratio (FRR 21 / 5 ).

[0083] In a further preferred embodiment, component BCL comprises or consists of a multimodal ethylene terpolymer.

[0084] Preferably, the multimodal ethylene terpolymer has a density of 915 kg / m 3 Up to 925kg / m 3 and an ethylene terpolymer having an MFR2 of 0.5 to 2.0 g / 10min.

[0085] The multimodal ethylene terpolymer preferably comprises or consists of a multimodal polymer of ethylene and at least two different comonomers selected from α-olefins having 4 to 10 carbon atoms, the multimodal ethylene terpolymer having an MFR of from 13 to 30. 21 / MFR2 ratio and MWD of 5 or less.

[0086] Such multimodal ethylene terpolymers are disclosed in, for example, WO2016 / 083208. For the definition of these ethylene terpolymers (such as the "modality" of the polymer) and production methods, see WO2016 / 083208. In addition, the density described in WO2016 / 083208 is between 915 and 925 kg / m 3 All embodiments and preferred embodiments of such ethylene terpolymers within the scope of are also preferred embodiments of the multimodal ethylene terpolymer in the present disclosure, whether explicitly described herein or not.

[0087] The multimodal ethylene terpolymer preferably has an MFR2 of 0.6 to 2.0 g / 10 min and particularly preferably 1.0 to 1.8 g / 10 min.

[0088] Preferably, the multimodal ethylene terpolymer has a 3 , more preferably 916 to 920 kg / m 3 density.

[0089] The multimodal ethylene terpolymer preferably has an MFR of 13 to 30, more preferably 15 to 25. 21 / MFR2 ratio.

[0090] The at least two α-olefin comonomers having 4 to 10 carbon atoms of the multimodal ethylene terpolymer are preferably 1-butene and 1-hexene.

[0091] Preferably, the total amount of comonomers present in the multimodal ethylene terpolymer BCL is from 0.5 to 10 mol%, more preferably from 1 to 8 mol%, even more preferably from 1 to 5 mol%, also preferably from 1.5 to 5 mol% and most preferably from 2.5 to 4 mol%.

[0092] The multimodal ethylene terpolymer is preferably a bimodal terpolymer, preferably comprising or consisting of an ethylene polymer component (BCL1) and an ethylene polymer component (BCL2), wherein the ethylene polymer component (BCL1) has a higher MFR2 than the ethylene polymer component (BCL2).

[0093] Preferably, the ethylene polymer component (BCL1) has an MFR2 of 1 to 50 g / 10 min, more preferably 1 to 40 g / 10 min, even more preferably 1 to 30 g / 10 min, yet more preferably 2 to 20 g / 10 min, yet more preferably 2 to 15 g / 10 min and most preferably 2 to 10 g / 10 min.

[0094] The ratio of the MFR2 of the ethylene polymer component (BCL1) to the MFR2 of the ethylene polymer component (BCL2) is preferably 2 to 50, more preferably 5 to 40, still more preferably 10 to 30, even more preferably 10 to 25 and most preferably 11 to 25.

[0095] Preferably, the ethylene polymer component (BCL1) comprises comonomers different from the ethylene polymer component (BCL2).

[0096] Preferably, the ethylene polymer component (BCL1) has a lower amount of comonomers (mol %) than the ethylene polymer component (BCL2), more preferably the ratio of [amount (mol %) of α-olefin comonomers having 4 to 10 carbon atoms present in the ethylene polymer component (BCL1)] to [amount (mol %) of at least two α-olefin comonomers having 4 to 10 carbon atoms of the final multimodal ethylene terpolymer BCL] is from 0.10 to 0.60, preferably from 0.15 to 0.50.

[0097] Preferably, the α-olefin comonomer having 4 to 10 carbon atoms of the ethylene polymer component (BCL1) is 1-butene, and the α-olefin comonomer having 4 to 10 carbon atoms of the ethylene polymer component (BCL2) is 1-hexene.

[0098] Preferably, the density of the ethylene polymer component (BCL1) is different from the density of the ethylene polymer component (BCL2), preferably higher than the density of the ethylene polymer component (BCL2).

[0099] The density of the ethylene polymer component (BCL1) is preferably from 925 to 950 kg / m 3 , more preferably 930 to 945 kg / m 3 .

[0100] Preferably, the multimodal ethylene terpolymer comprises an ethylene polymer component (BCL1) in an amount of 30 to 70 wt%, more preferably 40 to 60 wt%, even more preferably 35 to 50 wt%, yet more preferably 40 to 50 wt%; and an ethylene polymer component (BCL2) in an amount of 70 to 30 wt%, more preferably 60 to 40 wt%, even more preferably 50 to 65 wt%, yet more preferably 50 to 60 wt%, based on the total amount of the multimodal ethylene terpolymer BCL (100 wt%).

[0101] Most preferably, the multimodal ethylene terpolymer consists of ethylene polymer components (BCL1) and (BCL2) as the only polymer components. Thus, the split between ethylene polymer component (BCL1) and ethylene polymer component (BCL2) is (30 to 70):(70 to 30), preferably (32 to 60):(68 to 40), more preferably (35 to 50):(65 to 50), yet more preferably (40 to 50):(50 to 60).

[0102] In a preferred embodiment, the multimodal ethylene terpolymer has an MFR2 of 1.0 to 2.0 g / 10 min, and / or has a molecular weight distribution (MWD) of 3.0 to 5.0, and / or is a multimodal terpolymer of ethylene and two comonomers selected from α-olefins having 4 to 10 carbon atoms, preferably 1-butene and 1-hexene.

[0103] In a further preferred embodiment the multimodal ethylene terpolymer is a bimodal terpolymer comprising an ethylene polymer component (BCL1) and an ethylene polymer component (BCL2), wherein the ethylene polymer component (BCL1) has a higher MFR2 than the ethylene polymer component (BCL2), and the ethylene polymer component (BCL1) is a copolymer of ethylene and 1-butene, and the ethylene polymer component (BCL2) is a copolymer of ethylene and 1-hexene, preferably wherein the total comonomer content in the multimodal ethylene terpolymer is from 1 to 5 mol%.

[0104] In a particularly preferred embodiment, the multimodal ethylene terpolymer is a bimodal terpolymer, i.e. comprises a low molecular weight and a high molecular weight component and has an MFR2 of 1.0 to 1.8 g / 10min, and / or an MFR5 of 3.0 to 5.0 g / 10min, and / or an MFR of 20 to 40 g / 10min. 21 , and / or 916 to 920 kg / m3 density, and / or a molecular weight distribution (MWD) of 3.0 to 5.0, and / or an M of 15 to 25 kg / mol n , and / or 80 to 140 kg / mol of M w , and / or MFR of 15 to 25 21 / MFR2 ratio (FRR 21 / 2 ), and / or MFR of 6 to 9 21 / MFR5 ratio (FRR 21 / 5 ).

[0105] For all polymers described herein, unless otherwise stated, all molecular weight parameters are measured by GPC conventional methods as described in further detail below. Comonomer content is measured by NMR spectroscopy.

[0106] Preferred multimodal ethylene terpolymers are also commercially available products having the properties claimed herein, such as Anteo from Borealis or Borouge. TM , especially Anteo TM FK1828 or Anteo TM FK1820.

[0107] Component BCL is preferably present in the core layer composition in an amount of 20 to 50 wt%, more preferably 25 to 45 wt%, based on the total weight of the core layer composition of the turf film.

[0108] The BCL component is particularly suitable for imparting dart impact resistance and tear resistance to ground films while maintaining good optical and tensile properties.

[0109] The inner layer (IL) of the ground film is preferably made of an inner layer composition comprising components that particularly contribute to the mechanical properties of the film and maintain the optical properties of the film (low light transmittance).

[0110] Component AIL

[0111] The inner layer (IL) composition may comprise component AIL. Preferably, component AIL is a linear low density ethylene polymer (LLDPE).

[0112] Preferably, component AIL is a multimodal linear low density ethylene polymer, more preferably a multimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, such as a bimodal linear low density ethylene copolymer. More preferably, component AIL is a copolymer of ethylene and 1-butene or 1-hexene, most preferably a copolymer of ethylene and 1-butene.

[0113] Preferably, component AIL has a mass of 915 to 925 kg / m3 and an MFR2 measured according to ISO 1133 of 0.1 to 0.4 g / 10 min.

[0114] Such multimodal LLDPE and its production are described, for example, in WO 2004 / 000933 A1, pages 9 to 12.

[0115] Component AIL has 918 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a density of 0.1 to 0.4 g / 10min, more preferably 0.15 to 0.30 g / 10min.

[0116] Preferably, the total amount of comonomers present in component AIL is from 2.0 to 7.0 mol%, more preferably from 2.5 to 6.5 mol% and most preferably from 3.0 to 6.0 mol%.

[0117] In a particularly preferred embodiment, component AIL is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, most preferably 1-butene, and component AIL has an MFR2 of 0.15 to 0.30 g / 10min, and / or an MFR5 of 0.50 to 1.00 g / 10min and / or an MFR of 12 to 24 g / 10min. 21 , and / or 920 to 925 kg / m 3 density, and / or a molecular weight distribution (MWD) of 10 to 25, and / or an M of 10 to 18 kg / mol n , and / or 150 to 300 kg / mol of M w , and / or MFR from 60 to 150 21 / MFR2 ratio (FRR 21 / 2 ) and / or MFR from 16 to 30 21 / MFR5 ratio (FRR 21 / 5 ).

[0118] As component AIL, the resin Borstar FB1200 produced by Borouge can be used.

[0119] Preferably, component AIL is present in the inner layer composition in an amount of 50 to 90 wt%, more preferably 55 to 85 wt%, based on the total weight of the inner layer composition.

[0120] Component BIL

[0121] The inner layer (IL) of the ground film composition may further comprise a component BIL. Preferably, the component BIL is a linear low density ethylene polymer (LLDPE).

[0122] Preferably, component BIL is a multimodal linear low density ethylene polymer, more preferably a multimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, such as a bimodal linear low density ethylene copolymer. More preferably, component BIL is a copolymer of ethylene and 1-butene or 1-hexene, most preferably a copolymer of ethylene and 1-butene.

[0123] Preferably, component BIL has a mass of 915 to 925 kg / m 3 and an MFR2 measured according to ISO 1133 of 0.5 to 2.0 g / 10 min.

[0124] Such multimodal LLDPE and its production are described, for example, in WO 2021 / 013552.

[0125] Component BIL preferably has a mass of 915 to 920 kg / m 3 , more preferably 916 to 920 kg / m 3 and a density of 0.8 to 2.0 g / 10 min, more preferably 0.8 to 1.5 g / 10 min.

[0126] Preferably, the total amount of comonomers present in component BIL is from 7.0 to 13.0 wt.-%, preferably from 7.3 to 12.0 wt.-%, still more preferably from 7.5 to 11.5 wt.-% and most preferably from 7.7 to 11.0 wt.-%, based on the total weight of the monomer units in the BIL component.

[0127] Preferably, component BIL comprises or consists of two ethylene-1-butene copolymer fractions (BIL1) and (BIL2), wherein the first ethylene-1-butene copolymer fraction (BIL1) has a higher MFR2 than the second ethylene-1-butene copolymer fraction (BIL2).

[0128] The first ethylene-1-butene copolymer fraction (BIL1) has a 1-butene content of 0.5 to 7.5 wt%, preferably 0.6 to 5.0 wt%, still more preferably 0.7 to 3.5 wt% and most preferably 0.8 to 3.0 wt%, based on the total weight of monomer units in the first ethylene-1-butene copolymer fraction.

[0129] The first ethylene-1-butene copolymer fraction (BIL1) preferably has a carbonyl content of 915 kg / m3 Up to 955kg / m 3 , more preferably 925kg / m 3 Up to 950kg / m 3 And most preferably 935kg / m 3 Up to 945kg / m 3 density.

[0130] The first ethylene-1-butene copolymer fraction (BIL1) preferably consists of ethylene and 1-butene monomer units.

[0131] The first ethylene-1-butene copolymer fraction (BIL1) has a melt flow rate MFR2 of 1.0 g / 10 min to less than 50.0 g / 10 min, preferably 2.0 g / 10 min to 45.0 g / 10 min, still more preferably 3.0 g / 10 min to 30.0 g / 10 min, even more preferably 3.5 g / 10 min to 20.0 g / 10 min and most preferably 4.0 g / 10 min to 10.0 g / 10 min.

[0132] It is preferred that the first ethylene-1-butene copolymer fraction (BIL1) has a higher melt flow rate MFR2 than the second ethylene-1-butene copolymer fraction (BIL2). It is further preferred that the first ethylene-1-butene copolymer fraction (BIL1) has a higher melt flow rate MFR2 than component BIL.

[0133] A higher MFR2 value of the first ethylene-1-butene copolymer fraction (BIL1) indicates a lower molecular weight, such as a weight average molecular weight M of the first ethylene-1-butene copolymer fraction (BIL1) compared to the second ethylene-1-butene copolymer fraction (BIL2) and / or component BIL. w Lower.

[0134] The first ethylene-1-butene copolymer fraction (BIL1) is preferably present in component BIL in an amount of 30 to 47 wt%, more preferably 32 to 46 wt% and most preferably 35 to 45 wt%, based on the total weight of component BIL.

[0135] The first ethylene-1-butene copolymer fraction (BIL1) is typically polymerized as the first polymer fraction in a multistage polymerization process having two or more polymerization stages in sequence. Therefore, the properties of the first ethylene-1-butene copolymer fraction (BIL1) can be measured directly.

[0136] The second ethylene-1-butene copolymer fraction (BIL2) has a 1-butene content of 10.0 to 25.0 wt%, preferably 12.5 to 22.0 wt%, still more preferably 15.0 to 21.0 wt% and most preferably 16.0 to 20.0 wt%, based on the total weight of monomer units in the second ethylene-1-butene copolymer fraction.

[0137] The second ethylene-1-butene copolymer fraction (BIL2) preferably has a carbon content of 870 kg / m 3 Up to 912kg / m 3 , more preferably 880kg / m 3 Up to 910kg / m 3 And most preferably 890kg / m 3 Up to 905kg / m 3 density.

[0138] The second ethylene-1-butene copolymer fraction (BIL2) preferably consists of ethylene and 1-butene monomer units.

[0139] The second ethylene-1-butene copolymer fraction (BIL2) has a melt flow rate MFR2 of 0.05 g / 10 min to less than 1.0 g / 10 min, preferably 0.1 g / 10 min to 0.8 g / 10 min, still more preferably 0.2 g / 10 min to 0.7 g / 10 min and most preferably 0.3 g / 10 min to 0.6 g / 10 min.

[0140] It is further preferred that the second ethylene-1-butene copolymer fraction (BIL2) has a lower melt flow rate MFR2 than component BIL.

[0141] The lower MFR2 value of the second ethylene-1-butene copolymer fraction (BIL2) indicates a higher molecular weight, such as a weight average molecular weight M of the second ethylene-1-butene copolymer fraction (BIL2) compared to the first ethylene-1-butene copolymer fraction (BIL1) and / or component BIL. w higher.

[0142] The second ethylene-1-butene copolymer fraction (BIL2) is typically polymerized as a second polymer fraction in a multistage polymerization process having two or more polymerization stages in sequence in the presence of the first ethylene-1-butene copolymer fraction (BIL1). Therefore, the properties of the second ethylene-1-butene copolymer fraction (BIL2) cannot be measured directly but must be calculated. Suitable methods for calculating the comonomer content, density and MFR2 of the second ethylene-1-butene copolymer fraction (BIL2) are described in WO 2021 / 013552.

[0143] The second ethylene-1-butene copolymer fraction (BIL2) is preferably present in component BIL in an amount of 53 to 65 wt%, more preferably 54 to 63 wt% and most preferably 55 to 60 wt%, based on the total weight of component BIL.

[0144] The weight ratio of the first ethylene-1-butene copolymer fraction (BIL1) to the second ethylene-1-butene copolymer fraction (BIL2) in component BIL is preferably 35:65 to 47:53, more preferably 37:63 to 46:54 and most preferably 40:60 to 45:55.

[0145] In a preferred embodiment of the present invention, component BIL consists of a first ethylene-1-butene copolymer fraction (BIL1) and a second ethylene-1-butene copolymer fraction (BIL2).

[0146] In a particularly preferred embodiment of the second aspect, component BIL is a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer of ethylene and a comonomer selected from α-olefins having 4 to 10 carbon atoms, most preferably 1-butene, component BIL comprises two ethylene-1-butene copolymer fractions (BIL1) and (BIL2), and component BIL has an MFR2 of 0.8 to 1.5 g / 10min, and / or an MFR of 15 to 35 g / 10min. 21 , and / or 915 to 920 kg / m 3 density, and / or MFR of 15 to 25 21 / MFR2 ratio (FRR 21 / 2 ).

[0147] As component BIL, the resin Anbiq produced by Borouge can be used TM FM1810 or FM1818.

[0148] Preferably, component BIL is present in the inner layer composition in an amount of 10 to 50 wt%, more preferably 15 to 45 wt%, based on the total weight of the inner layer composition.

[0149] Particularly preferred is a rectangular polyethylene mulch film, more preferably a 3-layer rectangular polyethylene mulch film comprising at least 50 wt% of a polyethylene copolymer relative to the total weight of the rectangular polyethylene mulch film, the polyethylene copolymer having the properties listed above for AOL, ACL and AIL, in particular having a molecular weight of 915 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a density of 0.1 to 0.4 g / 10min, more preferably 0.1 to 0.3 g / 10min.

[0150] Furthermore, it is preferred that the rectangular polyethylene ground film is a 3-layer film, wherein at least one of the outer layers (i.e. the outer layer and / or the inner layer) comprises at least 50 wt.% of a polyethylene copolymer, preferably a linear low density ethylene polymer, preferably a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer, relative to the total weight of the respective layer, wherein the polyethylene copolymer has a molecular weight of 915 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a density of 0.1 to 0.4 g / 10min, more preferably 0.1 to 0.3 g / 10min.

[0151] In an alternative embodiment, the rectangular polyethylene ground film is a 3-layer film, wherein at least one exterior layer (i.e., the outer layer and / or the inner layer) comprises at least 50 wt. % polyethylene having the properties listed above for AOL, ACL and AIL, relative to the total weight of the respective layer.

[0152] It is particularly preferred that the rectangular polyethylene ground film is a 3-layer film, wherein at least one layer, preferably the core layer, comprises 20 to 50 wt.% of a component, relative to the total weight of the corresponding layer, which component is a linear low-density ethylene polymer, preferably a multimodal linear low-density ethylene polymer, more preferably a bimodal linear low-density ethylene terpolymer of ethylene and two comonomers selected from α-olefins having 4 to 10 carbon atoms, the component having a molecular weight of 915 to 925 kg / m 3 The present invention has a density of 0.5 to 2.0 g / 10 min and a melt flow rate (MFR2) determined according to ISO 1133.

[0153] In an alternative embodiment, the rectangular polyethylene ground film is a 3-layer film, wherein at least one layer, preferably the core layer, comprises 20 to 50 wt. % relative to the total weight of the respective layer of a component having the properties listed above for the BCL.

[0154] The thickness of the rectangular polyethylene ground film 1 is preferably in the range of 10 to 100 μm, more preferably in the range of 12 to 80 μm, and most preferably in the range of 15 to 70 μm.

[0155] The rectangular polyethylene ground film 1 preferably has a total light transmittance measured according to ASTM D1003 in the range of 0.0% to 3.0%, preferably in the range of 0.0% to 2.0%, and more preferably in the range of 0.0% to 1.0%.

[0156] The rectangular polyethylene ground film 1 preferably has a dart drop impact strength (DDI) measured according to ASTM D1709-A in the range of 2 to 10 g / μm, more preferably in the range of 2 to 8 g / μm, most preferably in the range of 3 to 6 g / μm.

[0157] The rectangular polyethylene ground film 1 preferably has a tensile modulus (1% secant) in the machine direction (MD) determined according to ASTM D882 in the range of 200 to 450 MPa and / or a tensile modulus (1% secant) in the transverse direction (TD) determined according to ASTM D882 in the range of 250 to 500 MPa.

[0158] The rectangular polyethylene ground film 1 preferably has a tensile stress at break in the machine direction (MD) measured according to ISO 527-3 in the range of 30 to 60 MPa, and / or a tensile stress at break in the transverse direction (TD) measured according to ISO 527-3 in the range of 10 to 40 MPa.

[0159] The rectangular polyethylene ground film 1 preferably has a nominal tensile strain at break in the machine direction (MD) determined according to ISO 527-3 in the range of 250 to 700%, and / or a nominal tensile strain at break in the transverse direction (TD) determined according to ISO 527-3 in the range of 350 to 800%.

[0160] The rectangular polyethylene ground film 1 preferably has a longitudinal (MD) tear strength measured according to ASTM D1922 in the range of 2 to 15 gf / μm, more preferably in the range of 4 to 12 gf / μm; and / or a transverse (TD) tear strength measured according to ASTM D1922 in the range of 10 to 40 gf / μm, more preferably in the range of 15 to 35 gf / μm.

[0161] In use, a single crop or a group of crops will grow within each perforation 2 of the mulch film 1. The inventors of the present invention have found that the positioning of the perforations in the mulch film, and therefore the spacing between the crops, is key to optimizing the crop yield from a given field area. This is particularly the case when the mulch film is used to grow rice, preferably when the mulch film has the absolute values ​​of A, B, C and D given above.

[0162] The choice of membrane material is also beneficial as a balance of impressive optical and mechanical properties is important to minimise water waste and avoid weed growth. When a membrane can be easily torn or punctured, weeds can easily grow in the holes. By avoiding tears and punctures, this risk is reduced.

[0163] Additionally, the film is able to prevent a significant amount of light from reaching areas of the soil that should not contain crops, ensuring that the light falls primarily on the crops and not on any weeds that may be present. High reflectivity is also important for helping to repel certain insects that are known to affect crop growth and for increasing the amount of light that reaches the leaves of the crop (i.e. for photosynthesis), where light is provided from both above and below.

[0164] The water barrier properties of polyethylene are also important for minimizing water wastage, where water evaporating from the soil surface is able to be recaptured as condensation on the membrane rather than simply escaping into the atmosphere.

[0165] Crop cultivation systems

[0166] In another aspect, the present invention is directed to a crop growing system.

[0167] A crop cultivation system according to another aspect comprises:

[0168] i) at least one plant bed 8;

[0169] ii) one rectangular polyethylene mulch film 1 according to the first aspect per plant bed, the one rectangular polyethylene mulch film 1 according to the first aspect per plant bed covering the plant bed 8; and

[0170] iii) A drip irrigation system comprising one drip line 6 per plant bed and a series of regularly spaced drip outlets 7 along the drip line 6 .

[0171] In other words, the crop cultivation system according to this aspect comprises:

[0172] i) at least one plant bed 8;

[0173] ii) one rectangular polyethylene mulch film 1 per plant bed, the one rectangular polyethylene mulch film 1 per plant bed covering the plant bed 8; and

[0174] iii) a drip irrigation system comprising one drip irrigation line 6 per plant bed and a series of regularly spaced drip outlets 7 along said drip irrigation line 6,

[0175] wherein each rectangular polyethylene mulch film 1 as a single layer film or a multilayer film has a regular array of perforations 2, the perforations 2 are symmetrically spaced along two lines 3 on both sides of a first axis 4, the first axis 4 is parallel to the length of the mulch film 1 and is located equidistant from the long side 5 of the mulch film 1, wherein each line 3 of perforations is parallel to the first axis 4, the shortest distance between the center of each perforation 2 and the first axis 4 is defined as A, wherein the perforations 2 are regularly spaced along the lines 3 parallel to the first axis 4, and there is a spacing defined as B between the centers of adjacent perforations 2 along either of the two lines 3, wherein B / A is in the range of 1.5 to 2.0, and

[0176] Each drip irrigation line is positioned along the first axis 4 of each ground film 1, and

[0177] The spacing between the drip outlets 7 along the drip irrigation line 6 is defined as E and E / B is in the range of 1.3 to 2.0.

[0178] Preferably, the crop growing system is a rice growing system.

[0179] The crop growing system can be best understood with reference to Figures 2a, 2b, 3a and 3b.

[0180] 2 a and 2 b depict a top view and a cross-sectional view of a crop cultivation system consisting of a single plant bed 8 , a single mulch film 1 , and a drip irrigation system consisting of a single drip irrigation line 6 .

[0181] The form of the plant bed 8 is therefore not particularly limited except that it must be a raised bank formed of soil for growing the target crop. The width of the top of the plant bed is defined as G.

[0182] G is preferably smaller than D (ie, smaller than the width of the mulch film) so that the mulch film 1 can completely cover the top surface of the plant bed and part or all of the sloping sides of the plant bed.

[0183] In one embodiment, the ratio of G / D is in the range of 0.3 to 0.8, more preferably in the range of 0.4 to 0.7, most preferably in the range of 0.4 to 0.6.

[0184] Furthermore, it is preferred that the absolute value of the distance G is within a range of 40 to 90 cm, more preferably within a range of 45 to 80 cm, and most preferably within a range of 50 to 70 cm.

[0185] There is no particular limitation on the height of the plant bed 8 , which can be different for different crops. A person skilled in the art should have no difficulty in selecting the appropriate height of the plant bed 8 .

[0186] The drip irrigation system comprises one drip irrigation line 6 per plant bed and a series of regularly spaced drip outlets 7 along the drip irrigation line 6 .

[0187] As depicted in FIGS. 2 a and 3 a , each drip irrigation line is positioned along the first axis 4 of each mulch film 1 .

[0188] In the simplest arrangement, where there is only one plant bed, as depicted in FIGS. 2 a and 2 b , the drip irrigation system consists of a single drip line 6 .

[0189] The drip irrigation lines 6 are pipes suitable for delivering water to the root zone of crops placed in the various perforations of the mulch film 1 .

[0190] In addition to water, drip irrigation systems can also be used to introduce fertilizers into the root zone, which is known in the art as fertigation. Those skilled in the art will be able to select the correct irrigation / fertigation method depending on the desired crop.

[0191] The cross-sectional shape of the drip irrigation line 6 is not limited. In some embodiments, the drip irrigation line is a perfectly round tube, while in other embodiments, the tube is somewhat flat (longer in the horizontal direction than in the vertical direction when installed). Figures 2a and 3a depict a slightly flattened cross-sectional shape; however, this is for illustration purposes only and should not be construed as a limitation on the shape of the drip irrigation line of the present invention.

[0192] Each drip irrigation line 6 preferably has a diameter of 50 to 400 mm. 2 range, more preferably 65 to 330 mm 2 range, most preferably between 80 and 260 mm 2 The cross-sectional area within the range.

[0193] Each drip line 6 preferably has a wall thickness in the range of 0.4 to 2.0 mm, more preferably in the range of 0.6 to 1.5 mm, most preferably in the range of 0.8 to 1.2 mm.

[0194] Each drip line 6 preferably has an outer diameter in the range of 8 to 25 mm, more preferably in the range of 10 to 24 mm, most preferably in the range of 12 to 20 mm.

[0195] Furthermore, each irrigation line 6 is preferably made of polyethylene, i.e., of an ethylene-based polymer containing at least 50 wt.% ethylene monomer. Preferably, the ethylene content of the ethylene-based polymer is at least 60 wt.%, more preferably at least 70 wt.%, still more preferably at least 80 wt.%, most preferably at least 90 wt.%. If comonomers are present in the polyethylene, it is preferred that any comonomer is selected from C3 to C 12 The alpha olefin is more preferably selected from C4 to C8 alpha olefins.

[0196] Preferably, the drip irrigation pipe comprises a high-density polyethylene resin component (containing 1.8 to 2.5 wt % carbon black) and has an MFR5 of 0.30 to 0.90 g / 10 min and / or an MFR of 10 to 20 g / 10 min. 21 , and / or 952 to 958 kg / m 3 density, and / or MFR of 20 to 28 21 / MFR5 ratio (FRR 21 / 5 ). As the HDPE component of the drip irrigation pipe, the resin Borstar HE1440 produced by Borouge can be used.

[0197] Alternatively or additionally, the drip irrigation pipe comprises a linear low density polyethylene component and has an MFR2 of 0.10 to 0.35 g / 10min and / or an MFR5 of 0.60 to 1.30 g / 10min and / or an MFR of 15 to 28 g / 10min. 21 , and / or 920 to 931 kg / m 3 density, and / or MFR of 70 to 120 21 / MFR2 ratio (FRR 21 / 2 ), and / or MFR of 18 to 28 21 / MFR5 ratio (FRR 21 / 5 ). As the LLDPE component of the drip irrigation pipe, the resin Borstar LE2270 produced by Borouge can be used.

[0198] In a preferred embodiment, the drip irrigation pipe comprises a mixture of 50 to 85 wt% of a linear low density polyethylene resin component as defined above and 15 to 50 wt% of a high density polyethylene resin component as defined above.

[0199] It is preferred that each irrigation line 6 comprises polyethylene in an amount in the range of 85 to 100 wt%, more preferably in the range of 90 to 100 wt%, most preferably in the range of 95 to 100 wt%.

[0200] In addition to the polyethylene as described above, each irrigation line 6 may also contain additives (Ad). The additives (Ad) are selected from additives known in the art, preferably from the group consisting of antioxidants, stabilizers, fillers, colorants, nucleating agents, antistatic agents and mixtures thereof.

[0201] These additives are generally commercially available and are described, for example, in “Plastic Additives Handbook” by Hans Zweifel, 5th edition, 2001, pages 871 to 873.

[0202] It is preferred that each irrigation line 6 contains the carbon black additive in an amount in the range of 0.5 to 5.0 wt %, more preferably in the range of 0.75 to 4.5 wt %, most preferably in the range of 1.0 to 4.0 wt %.

[0203] Preferably, the composition used for each irrigation line 6 has a tensile modulus (1 mm / min) determined from a compression molded specimen according to ISO 527-2 / 1A in the range of 150 to 1000 MPa, and / or a tensile stress at yield (50 mm / min) determined from a compression molded specimen according to ISO 527-2 / 1A in the range of 7 to 25 MPa.

[0204] As known in the art, the drip irrigation line can be located on the soil on the surface of the plant bed, buried under the soil or suspended above the soil. The drip irrigation line 6 of the crop cultivation system of the present invention is preferably located on the surface of the soil or buried under the soil. Most preferably, each drip irrigation line is located on the surface of the plant bed.

[0205] The drip irrigation line 6 has a series of regularly spaced drip outlets 7 along its length.

[0206] The nature of the drip outlets 7 is not particularly limited. They may be in the form of simple holes in the drip line 6, as depicted in Figure 2a, or alternatively may be in the form of smaller auxiliary tubes that deliver water from the drip line 6 to a location closer to the root zone of the crop.

[0207] The choice of which form the drip outlet 7 may take is within the skill of a person skilled in the art and may depend on the choice of crop.

[0208] Crucial to the second aspect of the invention is the spacing between the drip outlets, which spacing is defined as E.

[0209] In a second aspect, the ratio of E / B is in the range of 1.3 to 2.0, more preferably in the range of 1.4 to 1.8, most preferably in the range of 1.5 to 1.7.

[0210] For use in rice, it is preferred that the absolute value of E is in the range of 30 to 50 cm, more preferably in the range of 35 to 45 cm, most preferably in the range of 37 to 43 cm.

[0211] In a particular embodiment, distance A is in the range of 10 to 20 cm, distance B is in the range of 17 to 33 cm, distance C is preferably in the range of 3 to 12 cm, distance D is in the range of 60 to 210 cm, and distance E is in the range of 30 to 50 cm.

[0212] More preferably, distance A is in the range of 12 to 18 cm, distance B is in the range of 20 to 30 cm, distance C is preferably in the range of 4 to 11 cm, distance D is in the range of 75 to 180 cm and distance E is in the range of 35 to 45 cm.

[0213] Most preferably, distance A is in the range of 13 to 17 cm, distance B is in the range of 23 to 27 cm, distance C is preferably in the range of 5 to 10 cm, distance D is in the range of 90 to 150 cm and distance E is in the range of 37 to 43 cm.

[0214] The inventors of the present invention have discovered that the combination of drip line 6 and mulch film 1 helps maximize crop yield for a given plant bed 8. In particular, the relationship between spacing B and spacing E is critical to achieving optimal delivery of water while minimizing water waste.

[0215] 3a and 3b depict a top view and a cross-sectional view of a crop cultivation system consisting of a plurality of (eg, three) plant beds 8 , a plurality of (eg, three) mulch films 1 , and a drip irrigation system consisting of a central irrigation line 9 and a plurality of (eg, three) drip irrigation lines 6 .

[0216] In embodiments of the invention comprising a plurality of plant beds, the setup of each plant bed including associated mulch and drip lines is the same as the setup of the plant beds in the embodiments described above where there is only one plant bed.

[0217] When there is more than one plant bed (ie a plurality of plant beds), each drip irrigation line 6 is connected by a central irrigation line 9 which supplies each drip irrigation line 6 with water.

[0218] A plurality of drip irrigation lines 6 and a central irrigation line 9 form a drip irrigation system.

[0219] As depicted in FIGS. 3 a and 3 b , the drip lines 6 are positioned parallel to each other and preferably perpendicular to the central irrigation line 9 , wherein a regular spacing between the individual drip lines 6 is defined as F.

[0220] The ratio of F / D is preferably in the range of 0.9 to 1.5, more preferably in the range of 0.9 to 1.3, most preferably in the range of 0.9 to 1.2.

[0221] For use in rice, it is preferred that the absolute value of F is in the range of 60 to 210 cm, more preferably in the range of 75 to 180 cm, most preferably in the range of 90 to 150 cm.

[0222] In a particularly preferred embodiment, distance A is in the range of 10 to 20 cm, distance B is in the range of 17 to 33 cm, distance C is preferably in the range of 3 to 12 cm, distance D is in the range of 60 to 210 cm, distance E is in the range of 30 to 50 cm and distance F is in the range of 60 to 210 cm.

[0223] More preferably, distance A is in the range of 12 to 18 cm, distance B is in the range of 20 to 30 cm, distance C is preferably in the range of 4 to 11 cm, distance D is in the range of 75 to 180 cm, distance E is in the range of 35 to 45 cm and distance F is in the range of 75 to 180 cm.

[0224] Most preferably, distance A is in the range of 13 to 17 cm, distance B is in the range of 23 to 27 cm, distance C is preferably in the range of 5 to 10 cm, distance D is in the range of 90 to 150 cm, distance E is in the range of 37 to 43 cm and distance F is in the range of 90 to 150 cm.

[0225] As described above, the inventors of the present invention have discovered that the combination of drip irrigation lines 6 and mulch film 1 helps maximize crop yield for a given plant bed 8. In particular, the relationship between spacing B and spacing E is critical to achieving optimal water delivery while minimizing water waste. In addition, spacing F is important for systems with multiple plant beds, both in terms of maximizing water delivery and minimizing water waste. Correct spacing also allows farmers to easily access between plant beds, allowing them to adequately care for crops during crop growth, such as by weeding, as well as providing adequate ventilation.

[0226] picture

[0227] Figure 1 Ground film viewed from above

[0228] Figure 2a A single plant bed viewed from above

[0229] Figure 2b Cross section of a single plant bed

[0230] Figure 3a Multiple plant beds viewed from above

[0231] Figure 3b Cross-section of multiple plant beds

[0232] 1-Mulch

[0233] 2-Piercing

[0234] 3- Perforation Line

[0235] 4-First axis

[0236] 5-Long side of mulch

[0237] 6-Drip irrigation line

[0238] 7-Drip outlet

[0239] 8- Plant Bed

[0240] 9-Central irrigation pipeline

[0241] A - distance between the centers of two adjacent perforations

[0242] B - distance between each line of perforations and the first axis

[0243] C-hole diameter

[0244] D- Distance between the long sides of the mulch (width of the mulch)

[0245] E- The distance between each drip outlet

[0246] F- The distance between each drip irrigation line

[0247] G - Width of the top surface of the plant bed

[0248] Examples

[0249] A. Determination Method

[0250] The following definitions of terms and assay methods apply in the above general description of the invention as well as in the following examples, unless defined otherwise.

[0251] a) Measurement of melt flow rate (MFR)

[0252] The melt flow rate (MFR) is determined according to ISO 1133 and is expressed in g / 10 min. The higher the melt flow rate, the lower the viscosity of the polymer. The MFR of polyethylene is measured at 190°C and at 2.16 kg (MFR2), 5.00 kg (MFR5) or 21.6 kg (MFR 21 ) is measured under a load of .

[0253] The quantity FRR (Flow Rate Ratio) is an indicator of molecular weight distribution and represents the flow rate ratio under different loads. 21 / 5 Indicates MFR 21 / MFR5 value.

[0254] b) Density

[0255] The density of the polymers was determined according to ISO 1183-1:2004 (method A) on compression molded specimens prepared according to ISO 17855-2 and is reported in g / cm 3 Given as units.

[0256] c) GPC conventional method

[0257] The average molecular weight (M z 、M w and M n ), molecular weight distribution (MWD) and its polydispersity index PDI = M w / M n Describes the width (M n is the number average molecular weight, and M w is the weight average molecular weight) is determined by gel permeation chromatography (GPC) according to ISO 16014-1:2003, ISO 16014-2:2003, ISO 16014-4:2003 and ASTM D 6474-12 using the following formula:

[0258]

[0259] For a constant elution volume interval ΔV i , where A i and M i and elution volume V i Correlate the chromatographic peak slice area and the polyolefin molecular weight (MW), where N equals the number of data points obtained from the chromatogram between the integration limits.

[0260] Use and be equipped with the infrared (IR) detector (IR4 or IR5) from PolymerChar (Valencia, Spain) or the differential refractometer (RI) from Agilent Technologies, be equipped with the high temperature GPC instrument of 3x Agilent-PLgel Olexis and 1xAgilent-PLgel Olexis Guard column.Use 1,2,4-trichlorobenzene (TCB) stabilized with 250mg / L of 2,6-di-tert-butyl-4-methyl-phenol as mobile phase.Chromatographic system is operated under the column temperature of 160 ℃, the detector under 160 ℃ and the constant flow rate under 1mL / min.200 μ L sample solution is injected for each analysis.Use Agilent Cirrussoftware version 3.3 or PolymerChar GPC-IR control software to carry out data collection.

[0261] The column set was calibrated using 19 narrow MWD polystyrene (PS) standards ranging from 0.5 kg / mol to 11 500 kg / mol. The PS standards were dissolved at room temperature for several hours. The conversion of polystyrene peak molecular weight to polyolefin molecular weight was achieved by using the Mark Houwink equation and the following Mark Houwink constants:

[0262] K PS=19×10 -3 mL / g,α PS =0.655

[0263] K PE =39×10 -3 mL / g,α PE =0.725

[0264] A third-order polynomial fit was used to fit the calibration data.

[0265] All samples were prepared in a concentration range of approximately 1 mg / ml and dissolved in freshly distilled TCB stabilized with 250 ppm of Irgafos 168 for PE at 160°C for 3 (three) hours with continuous gentle shaking.

[0266] d) Comonomer content

[0267] Comonomer content (wt% and mole%) was determined by quantitative nuclear magnetic resonance (NMR) spectroscopy.

[0268] Use for 1 H and 13 Quantitative C was recorded in the melt on a Broker Avance III 500 NMR spectrometer operating at 500.13 and 125.76 MHz, respectively. 13 C{ 1 H} NMR spectroscopy. Nitrogen was used for all pneumatic devices and the temperature was 150 °C. 13 All spectra were recorded with a C-optimized 7 mm magic angle spinning (MAS) probe.

[0269] Approximately 200 mg of material was loaded into a 7 mm outer diameter zirconium oxide MAS rotor and spun at 4 kHz. This setup was chosen primarily for the high sensitivity required for rapid identification and accurate quantification {klimke06, parkinson07, castignolles09}. Standard single pulse excitation was used with a short recycle delay of 3 s using NOE {pollard04, klimke06} and RS-HEPT decoupling scheme {fillip05, griffin07}. A total of 1024 (1k) transients were collected for each spectrum.

[0270] Quantitative 13 C{ 1H} NMR spectra were processed, integrated and relevant quantitative properties were determined from the integration. All chemical shifts were internally referenced to the bulk methylene signal (δ+) {randall89} at 30.00 ppm. Characteristic signals {randall89} corresponding to 1-butene incorporation were observed, and the comonomer fraction was calculated as the fraction of 1-butene in the polymer relative to all monomers in the polymer.

[0271] The amount of isolated 1-butene incorporated into the EEBEE sequence was quantified using the integration of the *B2 site at 39.9 ppm, taking into account the number of reporting sites per comonomer:

[0272] B=I *B2

[0273] In the absence of other signals indicating other comonomer sequences (i.e., continuous comonomer incorporation), the total observed 1-butene comonomer content was calculated based on the amount of isolated 1-butene sequences only:

[0274] B total = B

[0275] The integration of the ααB2B2 sites at 39.4 ppm was used to quantify the amount of 1-butene incorporated continuously in the EEBBEE sequence, taking into account the number of reporting sites for each comonomer:

[0276] BB=2 * ΙααΒ2Β2

[0277] The amount of non-continuously incorporated 1-butene in the EEBEBEE sequence was quantified using the integration of the ββB2B2 sites at 24.7 ppm, taking into account the number of reporting sites for each comonomer:

[0278] BEB=2 * ΙββΒ2Β2

[0279] Since the isolated (EEBEE) and discontinuously incorporated (EEBEBEE) 1-butene * B2 and * The βΒ2Β2 sites overlap, so the total amount of isolated 1-butene incorporation was corrected based on the amount of non-contiguous 1-butene present:

[0280] B=I *B2 -2*I ββΒ2Β2

[0281] The total 1-butene content was calculated based on the sum of isolated, continuous and discontinuous incorporated 1-butene:

[0282] Total B=B+BB+BEB

[0283] Then, the total mole fraction of 1-butene in the polymer was calculated as:

[0284] fB=B total / (E total+B total+H total)

[0285] A characteristic signal corresponding to the incorporation of 1-hexene was observed {randall89} and the comonomer fraction was calculated as the fraction of 1-hexene in the polymer relative to all monomers in the polymer.

[0286] The amount of isolated 1-hexene incorporated in the EEHEE sequence was quantified using the integration of the *B4 site at 38.3 ppm, taking into account the number of reporting sites per comonomer:

[0287] H=1 *B4

[0288] The integration of the ααB4B4 sites at 40.5 ppm was used to quantify the amount of 1-hexene incorporated successively in the EEHHEE sequence taking into account the number of reporting sites for each comonomer:

[0289] HH=2*IααB4B4

[0290] The integration of the ββB4B4 sites at 24.7 ppm was used to quantify the amount of 1-hexene incorporated non-continuously in the EEHEHEE sequence taking into account the number of reporting sites for each comonomer:

[0291] HEH=2*IββB4B4

[0292] Due to the overlap of signals from the *B4 and *ββB4B4 sites of isolated (EEHEE) and discontinuous (EEHEHEE) incorporated 1-hexene, respectively, the total amount of isolated 1-hexene incorporation was corrected based on the amount of discontinuous 1-hexene present:

[0293] H=I *B4 -2*ΙββΒ4Β4

[0294] The total 1-hexene content was calculated based on the sum of isolated, continuous and non-continuous incorporated 1-hexene:

[0295] H total = H + HH + HEH

[0296] Then, the total mole fraction of 1-hexene in the polymer was calculated as:

[0297] fH=H total / (E total+B total+H total)

[0298] The amount of ethylene was quantified using the integration of the bulk methylene (δ+) sites at 30.00 ppm. This integration includes the γ sites from 1-hexene as well as the 3B4 sites. The total ethylene content was calculated based on the bulk integration and compensation for the observed 1-butene and 1-hexene sequences and end groups:

[0299] E=I δ+ / 2

[0300] Characteristic signals arising from saturated end groups were observed. The content of such saturated end groups was quantified using the average of the integration of the signals at 22.8 and 32.2 ppm, respectively, attributable to the 2s and 3s sites:

[0301] S=(1 / 2)*(I 2S +I 3S )

[0302] Correction for the presence of isolated comonomer units is based on the number of comonomer units and saturated end groups present:

[0303] Total E=E+(§ / 2)*B+(2 / 2)*H+(1 / 4)*HH+(3 / 4)*HEH+(3 / 2)*S

[0304] The mole percentage of comonomer incorporation is calculated from the mole fraction:

[0305] B [mol %] = 100 * fB

[0306] H [mol %] = 100 * fH

[0307] The weight percent of incorporated comonomer is calculated from the mole fraction:

[0308] B [weight %] = 100 * (fB * 56.11) / ((fB * 56.11) + (fH * 84.16) + ((1 - (fB + fH)) * 28.05))

[0309] H [weight %] = 100 * (fH * 84.16) / ((fB * 56.11) + (fH * 84.16) + ((1 - (fB + fH)) * 28.05))

[0310] randalI89: J. Randall, Macromol. Sci., Rev. Macromol. Chcm. Phys. 1989, C29, 201.

[0311] klimke06: Klimke, K., Parkinson, M., Piel, C, Kaminsky, W., Spiess, HW, Wilhelm, M., Macromol. Chem. Phys. 2006; 207:382.

[0312] parkinson07: Parkinson, M., Klimke, K., Spiess, HW, Wilhelm, M., Macromol. Chem. Phys. 2007; 208:2128.

[0313] pollard04: Pollard, M., Klimke, K., Graf, R., Spiess, HW, Wilhelm, M., Sperber, O., Piel, C, Kaminsky, W., Macromolecules 2004;37:813.

[0314] filip05:Filip,X.,Tripon,C,Filip,C,J.Mag.Resn.2005,176,239.

[0315] griffin07: Griffin, JM, Tripon, C, Samoson, A., Filip, C, and Brown, SP, Mag. Res. in Chem. 2007 45, SI, S198.

[0316] castignolles09:Castignolles,P.,Graf,R.,Parkinson,M.,Wilhelm,M.,Gaborieau,M.,Polymer50(2009)2373.

[0317] e) Mechanical properties

[0318] The tensile properties of polyethylene resins were determined on molded specimens with a sample thickness of 4 mm prepared from compression molded plaques. The tensile modulus was determined according to ISO 527-2 / 1A at 1 mm / min and 23° C. For determination of the yield stress, a test speed of 50 mm / min was used.

[0319] Tensile modulus and tensile stress at break of membranes

[0320] The tensile properties of the films were determined according to ISO 527-3 at 23°C using blown films using specimen type 2. The tensile modulus in the machine direction (MD) and transverse direction (TD) were determined according to ASTM D882 as 1% secant modulus at a test speed of 5 mm / min and a gauge length of 50 mm.

[0321] The tensile stress at break of the films was determined according to ISO 527-3, test specimen type 2, with a gauge length of 50 mm and a test speed of 500 mm / min. The film samples were produced as described in the "Examples" below.

[0322] Nominal tensile strain at break of the membrane

[0323] Nominal tensile strain at break in the machine direction (MD) and in the transverse direction (TD) were measured according to ISO 527-3 on films having the indicated thickness, which were produced as described in the Examples below.

[0324] Tear strength of film

[0325] Machine direction (MD) Elmendorf tear strength and transverse direction (TD) Elmendorf tear strength are measured according to ASTM D1922 or ISO 6383-2 and are reported in Newtons (N) or grams-force (gf).

[0326] The tear strength per unit thickness (gf / μm) was calculated by dividing the Elmendorf tear strength (in gf) by the thickness of the film (in μm).

[0327] Dart impact strength

[0328] The dart drop impact strength (DDI) of the films was measured according to ASTM D1709, Method "A", on films having the indicated thickness, produced as described in the Examples below, and is reported in grams (g).

[0329] The DDI per unit thickness (in g / μm) is calculated by dividing the DDI (in grams) by the thickness of the film (in μm).

[0330] f) Total light transmittance

[0331] The total light transmittance of plastic film is determined according to ASTM D 1003 and ISO 14782. The total transmittance is the ratio of transmitted light to incident light, measured using a hazemeter. It is affected by absorption and reflection characteristics. The total transmitted light consists of a direct transmission component and a diffuse component.

[0332] B. Examples

[0333] An experimental rice field (ie, a rice field) was established using the crop cultivation system of the present invention.

[0334] The ground film is a 3-layer film, wherein each layer is a polyethylene layer containing appropriate additives (see Table 1). The outer layer, core layer and inner layer are present in a thickness ratio of 1:1:1 (OL:CL:IL). The composition of each layer is given in Table 1:

[0335] Table 1: Mulch film formula

[0336]

[0337] The properties of the polymers used in the mulch films are given in Table 2:

[0338] Table 2: Base polymers for ground membranes

[0339]

[0340] The masterbatch formula used in the preparation is as follows:

[0341] Plasblak PE2772, commercially available from Cabot India Ltd., was used as the black masterbatch.

[0342] UV Masterbatch 20, commercially available from Polmann India Ltd., was used as UV protection masterbatch.

[0343] Blend Silver 4906, commercially available from Blend colours Pvt. Ltd., India, was used as the "silver masterbatch".

[0344] The mulch films were produced on a Polyrema (Reifenhauser blown film line with internal bubble cooling system) with an output of 150 kg / h and a cooling air temperature between 12 and 16° C. The detailed parameters and temperature profiles used to prepare the mulch films are listed in Tables 3 and 4 below.

[0345] Table 3: Blown film line parameters.

[0346]

[0347] Table 4 lists the temperature profile of the blown film line, ie the temperatures for the different layers of the blown film extruder at different positions of the blown film line.

[0348] Table 4: Temperature profile of the blown film line (°C).

[0349]

[0350] During field use, the outer layer of the mulch is exposed to direct sunlight (ie, toward the atmosphere), while the inner layer of the mulch is exposed to the soil (ie, toward the ground).

[0351] The shape of the ground film is as described in the specification, wherein A=15 cm, B=25 cm, C=5 cm, and D=120 cm.

[0352] The mechanical / optical properties of the film are described in Table 5:

[0353] Table 5: Mechanical and optical properties of the ground film of the present invention

[0354]

[0355] The drip line is formed from a 70:25:5 blend of LLDPE:HDPE:CBM and has an outer diameter of 16 mm, a wall thickness of approximately 1 mm, and thus a cross-sectional area of ​​approximately 150 mm. 2 As LLDPE, a polyol with an MFR2 of 0.22 g / 10 min and a polyol with an MFR of 0.926 g / cm 3 Borstar resin LE2270 with a density of 0.60 g / 10 min and 0.956 g / cm 3 Borstar resin HE1440 with a density of 1.34 Å. CBM is a carbon black masterbatch Plasblak PE2772 commercially available from Cabot India Ltd.

[0356] The drip outlets were regularly spaced at 40 cm intervals (E = 40 cm) and the drip lines were spaced at 120 cm intervals (F = 120 cm) along the central irrigation line.

[0357] The plant bed was formed by raising the soil to a bank approximately 20 to 30 cm high with a top width of 60 cm (G = 60 cm).

[0358] Once the crop cultivation system is assembled and the plant beds are pre-irrigated, the rice seedlings are placed into the perforations of the mulch film. Both the mulch film and the drip irrigation lines can be easily laid using a tractor without causing any damage to either component.

[0359] The drippers were set to discharge 4 liters per hour and the plant beds were irrigated for 15 minutes every day until 10 days before harvest (harvest was carried out on day 120 after planting). Depending on local weather conditions, daily irrigation was not necessary.

[0360] Just four to five days after planting, over 95% of the seedlings were well established.

[0361] After harvest, the mulch can be easily removed, minimizing the accumulation of plastic debris and soil contamination.

[0362] By using the crop cultivation system of the present invention, crop yields can be increased (6.5 to 8.0 tons of rice per hectare) while using less seeds (4 to 5 kg per acre) than conventional methods (4.5 to 5.5 tons of rice per hectare and 12 to 15 kg of seeds per acre). Compared to conventional methods, water consumption is greatly reduced, requiring only 2,000 to 3,000 liters of water per kg of rice, while 4,500 to 5,000 liters of water are normally required.

[0363] Furthermore, when using the crop cultivation system of the present invention, minimal weed growth was observed, which means that farmers do not need to intensively weed the crops during their growth. The grown rice was also healthier than conventionally grown rice, which may be due to the minimized reduction of pests and weeds and the optimized growing conditions (i.e., light, water, and optional fertilizers). It was also observed that the husk to grain ratio during milling was improved.

[0364] Finally, the straw collected from the rest of the plant provides improved cattle feed, allowing for easier crop rotation, thereby improving land utilization.

[0365] Overall, taking into account the above factors, an increase in productivity of 25% to 35% was calculated relative to conventional rice cultivation methods.

Claims

1. A crop cultivation system, comprising: i) at least one plant bed (8); ii) one rectangular polyethylene mulch film (1) per plant bed, said one rectangular polyethylene mulch film (1) per plant bed covering said plant bed (8); and iii) a drip irrigation system comprising one drip irrigation line (6) per plant bed and a series of regularly spaced drip outlets (7) along the drip irrigation line (6), wherein each rectangular polyethylene ground film (1) as a single-layer film or a multi-layer film has a regular array of perforations (2), the perforations (2) are symmetrically spaced along two lines (3) on both sides of a first axis (4), the first axis (4) is parallel to the length of the ground film (1) and is located equidistant from the long side (5) of the ground film (1), wherein each line (3) of perforations is parallel to the first axis (4), the shortest distance between the center of each perforation (2) and the first axis (4) is defined as A, wherein the perforations (2) are regularly spaced along the lines (3) parallel to the first axis (4), and there is a spacing defined as B between the centers of adjacent perforations (2) along any of the two lines (3), wherein B / A is in the range of 1.5 to 2.0, and wherein each drip irrigation line is positioned along the first axis (4) of each ground film (1), and The spacing between the drip outlets (7) along the drip irrigation line (6) is defined as E, and E / B is in the range of 1.3 to 2.

0.

2. A crop cultivation system according to claim 1, wherein the perforations (2) of the rectangular polyethylene mulch film (1) are substantially circular and have a diameter defined as C, wherein C / A is in the range of 0.20 to 0.

75.

3. The crop cultivation system according to claim 1 or claim 2, wherein the rectangular polyethylene ground film (1) is a multi-layer film, more preferably a 3-layer film.

4. A crop cultivation system according to any one of the preceding claims, wherein the rectangular polyethylene mulch film (1) has a total light transmittance measured according to ASTM D1003 in the range of 0.0% to 3.0%, preferably in the range of 0.0% to 2.0% and more preferably in the range of 0.0% to 1.0%.

5. A crop cultivation system according to any of the preceding claims, wherein the rectangular polyethylene mulch film (1) has a dart impact strength (DDI) measured according to ASTM D 1709 / A in the range of 2 to 10 g / μm, more preferably in the range of 2 to 8 g / μm, most preferably in the range of 3 to 6 g / μm, and / or a longitudinal (MD) tear strength (elmendorf) measured according to ASTM D1922 in the range of 2 to 15 gf / μm, more preferably in the range of 4 to 12 gf / μm.

6. The crop cultivation system according to any one of the preceding claims, wherein the rectangular polyethylene mulch film (1) has a thickness in the range of 10 to 100 μm, more preferably in the range of 12 to 80 μm, most preferably in the range of 15 to 70 μm.

7. The crop cultivation system according to any one of the preceding claims, wherein the distance between the long sides of the rectangular polyethylene mulch film (1) is defined as D, and D / A is in the range of 4 to 14.

8. A crop cultivation system according to any one of the preceding claims, wherein A is in the range of 10 to 20 cm, B is in the range of 17 to 33 cm and E is in the range of 30 to 50 cm.

9. The crop cultivation system according to any one of the preceding claims, wherein the rectangular polyethylene mulch film (1) comprises at least 50% by weight of a polyethylene copolymer relative to the total weight of the rectangular polyethylene mulch film (1), the polyethylene copolymer having a molecular weight of 915 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a melt flow rate (MFR2) determined according to ISO 1133 of 0.1 to 0.4 g / 10 min, more preferably 0.1 to 0.3 g / 10 min.

10. The crop cultivation system according to any one of the preceding claims, wherein the rectangular polyethylene mulch film (1) is a 3-layer film, wherein at least one outer layer comprises at least 50 wt.-% of a polyethylene copolymer, preferably a linear low density ethylene polymer, preferably a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene copolymer, relative to the total weight of the corresponding layer, wherein the polyethylene copolymer has a molecular weight of 915 to 925 kg / m 3 , more preferably 920 to 925 kg / m 3 and a melt flow rate (MFR2) determined according to ISO 1133 of 0.1 to 0.4 g / 10 min, more preferably 0.1 to 0.3 g / 10 min.

11. The crop cultivation system according to any one of the preceding claims, wherein the rectangular polyethylene mulch film (1) is a 3-layer film, wherein at least one layer, preferably the core layer, comprises 20 to 50 wt.% of a component, relative to the total weight of the corresponding layer, which component is a linear low density ethylene polymer, preferably a multimodal linear low density ethylene polymer, more preferably a bimodal linear low density ethylene terpolymer of ethylene and two comonomers selected from α-olefins having 4 to 10 carbon atoms, wherein the component has a molecular weight of 915 to 925 kg / m 3 The present invention has a density of 0.5 to 2.0 g / 10 min and a melt flow rate (MFR2) determined according to ISO 1133.

12. A crop growing system according to any one of the preceding claims, wherein each drip irrigation line is located on the surface of a plant bed.

13. A crop cultivation system according to any one of the preceding claims, comprising a plurality of plant beds, wherein the drip irrigation system comprises a plurality of drip irrigation lines (6) connected by a central irrigation line (9), the plurality of drip irrigation lines (6) being positioned parallel to each other at a regular spacing defined as F, wherein F / D is in the range of 0.9 to 1.

5.

14. A crop growing system according to any one of the preceding claims which is a rice growing system.

15. The rectangular polyethylene ground film (1) according to any one of claims 1 to 11.

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